RURAL  TEXT-BOOK 
SERIES 


1 


HORTICULTURE 

FOR 
SCHOOLS 


STUBENRAUCH 
WOOD 
BOOTH 


L.  H.  BAILEY 
EDITOR 


it 


•4AIN  LIBRARY-AGRICULTURE  Ol 


Ube  IRural  UextXBoofe  Series 

EDITED  BY  L.  H.  BAILEY 


HORTICULTURE  FOR  SCHOOLS 


Sty?  Sural  3foet-$00k 

EDITED  BY  L.  H.  BAILEY 

Bailey:  SCHOOL  BOOK  OF  FARMING. 

Carleton:  THE  SMALL  GRAINS. 

B.  M.  Duggar:  PLANT  PHYSIOLOGY. 

J.  F.  Duggar:  SOUTHERN  FIELD  CROPS. 

Fisk:  BOOK  OF  ICE  CREAM. 

Gay:  BREEDS  OF  LIVE-STOCK. 

Gay:  PRINCIPLES  AND    PRACTICE   OF    JUDGING 

LIVE-STOCK. 

Goff:  PRINCIPLES  OF  PLANT  CULTURE. 
Gourley:  TEXT-BOOK  OF  POMOLOGY. 
Guthrie:  BOOK  OF  BUTTER. 
Harper:  ANIMAL  HUSBANDRY  FOR  SCHOOLS. 
Harris  and  Stewart:  PRINCIPLES  OF  AGRONOMY. 
Hitchcock:  TEXT-BOOK  OF  GRASSES. 
Jeffery:  TEXT-BOOK  OF  LAND  DRAINAGE. 
Jordan:  FEEDING  OF  ANIMALS,  Revised. 
Livingston:  FIELD  CROP  PRODUCTION. 
Lyon:  SOILS  AND  FERTILIZERS. 
Lyon,    Pippin,    and    Buckman:    SOILS,    THEIR 

PROPERTIES  AND  MANAGEMENT. 
Mann:  BEGINNINGS  IN  AGRICULTURE. 
Montgomery:  THE  CORN  CROPS. 
Morgan:  FIELD  CROPS  FOR  THE  COTTON-BELT. 
Mumford:  THE  BREEDING  OF  ANIMALS. 
Piper:   FORAGE  PLANTS  AND  THEIR  CULTURE. 
Sampson:  EFFECTIVE  FARMING. 
Stubenrauch,  Wood,  and  Booth:  HORTICULTURE 

FOR  SCHOOLS. 

Thorn  and  Fisk:  THE  BOOK  OF  CHEESE. 
Warren:  ELEMENTS  OF  AGRICULTURE. 
Warren:  FARM  MANAGEMENT. 
Wheeler:  MANURES  AND  FERTILIZERS. 
White:  PRINCIPLES  OF  FLORICULTURE. 
Widtsoe:  PRINCIPLES  OF  IRRIGATION  PRACTICE. 


HORTICULTURE    FOR 
SCHOOLS 


BY 

the  late 

A.  V.  STUBENRAUCH 

\\ 

PROFESSOR    OF    POMOLOGY,    UNIVERSITY    OF    CALIFORNIA 

MILO  N.  WOOD 

FORMERLY    OF    THE    DEPARTMENT    OF    POMOLOGY,    UNIVERSITY    OF    CALIFORNIA 

AND 

CHARLES   J.  BOOTH 

INSTRUCTOR    OF    HORTICULTURE,    CHAFFEY   UNION    HJGH    SCQOOL 


THE  MACMILLAN     COMPANY 
1922 

All  rights  reserved 


'Printed  in  the  United  States  of  America 


AGrt/C. 


Copyright,  1922 
BY  THE  MACMILLAN  COMPANY 


Set  up  and  electrotyped.      Published  December,  1922 
MAifcl  LIBRARY-AGRICULTURE  DElT. 


EXPLANATION 

THE  late  Professor  A.  V.  Stubenrauch  was  under  contract 
at  the  time  of  his  death  to  prepare  an  elementary  text-book 
of  horticulture,  suitable  for  use  in  the  schools  and  in  reading- 
courses.  Much  of  the  material  had  been  assembled  by  him. 
It  has  seemed  best  to  bring  the  book  to  completion,  pre- 
serving as  much  as  possible  of  his  method  and  point  of  view. 
This  work  has  fallen  to  Milo  N.  Wood,  who  was  personally 
associated  with  Professor  Stubenrauch  in  his  teaching; 
and  the  enterprise  has  been  joined  by  Charles  J.  Booth,  an 
active  teacher  of  the  subject  in  high -school. 

Professor  Stubenrauch  was  connected  with  the  University 
of  California  at  the  time  of  his  death.  He  was  a  graduate  of 
that  institution,  a  post-graduate  of  Cornell  University,  a 
professor  in  the  University  of  Illinois,  and  later  prominently 
connected  with  the  United  States  Department  of  Agriculture 
in  its  country-wide  pomological  work.  He  was  a  man  of 
wide  friendships,  solid  personal  attainments,  inspiring  teach- 
ing ability,  and  excellent  qualifications  for  investigation. 
His  death  early  in  1917,  as  he  was  entering  the  productive 
period  of  manhood,  deprived  the  people  of  a  forceful  and 
dependable  leader. 

Another  book  was  under  preparation  by  Professor  Stuben- 
rauch, and  it  is  intended  that  it  shall  be  brought  to  com- 
pletion. There  are  no  other  books  bearing  his  name,  al- 
though he  had  large  plans  as  an  author.  It  is  not  expected 
that  these  books  can  carry  out  his  style  and  contain  all  his 
subject-matter;  but  his  collaborators  have  been  glad  to  do 
their  best  to  complete  his  labors. 

L.  H.  BAILEY. 

498381 


PREFACE 

This  book  is  intended  as  a  text-book  of  horticulture  for 
high-schools  and  for  other  schools  requiring  a  text  for  pupils 
of  high-school  grade,  and  also  for  use  in  homes  and  reading- 
courses.  The  subject-matter  and  exercises  may  be  covered  in 
one  school  year  if  three  periods  a  week  are  spent  in  recitation 
and  two  double  periods  are  employed  for  laboratory  work. 
When  a  shorter  period  is  given  to  the  subject,  it  will  -be 
advisable  to  omit  the  chapters  of  least  importance  to  the 
community. 

It  is  not  necessary  that  the  chapters  be  studied  in  the  order 
given  in  the  text.  The  teacher  should  assign  them  in  the 
order  suggested  by  the  climate,  season,  and  needs  of  the 
locality.  It  is  advisable,  however,  to  take  up  chapters  I  and 
II  before  other  subject-matter  is  considered,  because  an 
understanding  of  the  material  contained  therein  will  result 
in  a  more  thorough  appreciation  of  the  chapters  following. 

The  exercises  given  at  the  ends  of  the  chapters  are  in- 
tended as  an  aid  to  the  busy  teacher.  They  are  of  three 
types:  (1)  those  that  explain  or  illustrate  the  subject-matter 
in  the  text;  (2)  those  that  familiarize  the  pupils  with  the 
best  horticultural  practices;  and  (3)  project  exercises  that 
require  the  pupils  to  apply  the  facts,  principles,  and  methods 
of  procedure  in  detail  to  the  production  and  sale  of  a  par- 
ticular horticultural  crop. 

The  project  exercise  is  of  great  value  in  teaching  the 
practical  application  of  the  general  principles  discussed  in 
the  text,  and  in  teaching  practical  business  methods  as 
applied  to  horticulture.  In  general  the  project  should  be 
large  enough  to  occupy  the  spare  time  of  the  student  and 

vii 


VUl  PREFACE 

may  be  of  such  size  as  to  be  of  considerable  commercial  or 
productive  importance.  Care  should  be  taken,  however, 
that  the  project  is  not  so  large  that  the  student  cannot  care 
for  it  properly.  While  a  few  trees  or  a  small  plot  of  ground 
may  not  always  supply  the  same  aspects  as  would  a  large 
planting,  the  problems  relating  to  successful  production  are, 
for  practical  purposes,  identical.  It  is  desirable  that  projects 
in  horticulture  be  carried  on  by  the  student  at  home  in  coopera- 
tion with  his  parents  and  under  the  direction  of  the  teacher 
of  agriculture.  Sometimes  the  necessary  land  and  materials 
may  be  rented.  The  teacher  should  supervise  the  keeping  of 
careful  records  of  operations,  expenses,  and  disposition  of  the 
products.  Any  financial  or  other  returns  should  go  to  the 
student.  Student  projects  on  the  school  ground  are  generally 
to  be  discouraged.  Orchards  and  gardens  on  the  school 
grounds,  however,  are  of  great  value  as  out-of-door  labor- 
atories in  which  the  student  may  gain  experience  in  horti- 
cultural practice.  They  may  be  of  the  school  garden  kind. 

It  is  of  great  value  to  the  student  to  have  access  to  good 
reference  literature.  Bailey's  Standard  Cyclopedia  of  Hor- 
ticulture (6  vols.)  will  be  useful.  Many  valuable  works  on 
special  horticultural  topics  are  now  available.  The  teacher 
should  choose  as  reference  books  such  of  these  works  as 
seem  best  adapted  to  the  needs  of  the  locality.  Such  farmers' 
bulletins  and  technical  publications  on  horticultural  subjects 
as  may  be  obtained  from  the  United  States  Department  of 
Agriculture  and  the  State  Experiment  Stations  are  very 
helpful. 

Special  acknowledgment  is  due  L.  H.  Bailey,  for  helpful 
counsel  and  valuable  criticism;  also  to  W.  L.  Howard, 
Professor  of  Pomology,  University  of  California  Deciduous- 
Fruit  Experiment  Station;  J.  W.  Lloyd,  Professor  of  Oleri- 
culture, University  of  Illinois;  W.  F.  Lusk,  Head  of  Depart- 
ment of  Rural  Education,  Mississippi  Agricultural  and 
Mechanical  College;  W.  P.  Tufts,  Professor  of  Pomology  of 


PREFACE  ix 

the  University  of  California  Farm  School;  J.  C.  Whitten,  late 
Professor  of  Pomology,  University  of  California;  A.  T.  Potts, 
Professor  of  Vegetable  Gardening  in  the  Agricultural  and 
Mechanical  College  of  Texas;  and  T.  J.  Talbert,  Superin- 
tendent of  Extension  Schools,  Kansas  Agricultural  College, 
for  reading  and  criticizing  parts  of  the  manuscript.  George 
P.  Weldon,  Pomologist  of  the  Chaffey  Junior  College  gave 
valuable  assistance  in  the  preparation  of  the  chapter  on 
insects. 

The  line  drawings  were  made  specially  for  this  book  by 
R.  C.  Steadman  of  the  United  States  Department  of  Agri- 
culture, by  B.  F.  Williamson  of  New  York,  and  by  Mary 
Mekeel,  of  Ithaca,  N.  Y.  The  University  of  California 
allowed  the  use  of  certain  material  prepared  by  the  writers 
while  they  were  connected  with  the  institution,  and  supplied 
photographs.  Several  figures  were  taken  from  School  Agri- 
culture. A.  D.  Shamel  of  the  United  States  Department  of 
Agriculture  furnished  photographs;  also  H.  S.  Fawcett  and 
H.  J.  Quayle  of  the  Citrus  Experiment  Station  of  Cali- 
fornia, Porter  J.  Preston  and  L.  S.  Armstrong.  Figures  2 
and  25  were  drawn  by  R.  A.  Hopkins,  and  figure  121  by 
A.  A.  Brown  of  Ontario,  California.  Figures  17,  29,  39, 
111,  117,  and  118  are  taken  from  the  publications  of  the 
Macmillan  Company. 

MILO  N.  WOOD. 

CHARLES  J.  BOOTH. 
September  1,  1922. 


TABLE  OF  CONTENTS 

(Numbers  in  the  text  refer  to  paragraphs.) 

CHAPTER  I  PAGES 

HORTICULTURE  AND  PLANT  IMPROVEMENT 3-15 

Horticulture  denned,  1;  Plant  material,  2;  Va- 
rieties not  permanent,  3;  Change  is  universal,  4; 
The  nightshade  family,  5;  The  potato,  6;  Inter- 
grafting,  7;  Domestication,  8;  American  wild  plants, 
9.  The  Process  of  Improvement:  Darwin,  10;  The 
origin  of  species,  11;  Mendel,  12;  Mendel's  law,  13; 
Dominant  and  recessive  characters,  14;  De  Vries, 
15;  The  mutation  theory,  16;  Plant  improvement 
a  division  of  science,  17;  Hybridization,  18;  One 
effect  of  hybridization,  19;  Bud-selection,  20;  Ways 
in  which  plants  vary,  21;  Life  forms  not  fixed,  22; 
Modern  conditions  demand  the  best,  23;  The  goal, 
24. 

CHAPTER  II 

THE  LIVING  PLANT 16-38 

Parts  of  plants,  25;  The  cell,  26;  Number  of  cells 
necessary  to  plant  life,  27;  Structure  of  plant-cells, 
28;  The  cell-wall,  29;  The  ectoplasm,  30;  Pro- 
toplasm, 31;  The  nucleus,  32;  Cytoplasm,  33; 
Vacuoles,  34;  Plastids,  35;  Functions  of  plant  parts, 
36;  Roots,  37;  Manner  of  growth  of  roots,  38; 
Functions  of  roots,  39;  The  stem,  40;  Structure  and 
functions  of  the  stem,  41;  Growth  of  stems,  42; 
Buds,  43;  Fruit-buds,  44;  The  leaves,  45;  Structure 
of  leaves,  46;  The  functions  of  leaves,  47. 

CHAPTER  III 

PROPAGATION  BY  SEEDS 39-53 

Sexual  reproduction,  48;  Structure  of  the  seed,  49; 

The  pea,  50;   The  bean,  51;  The  pumpkin  seed,  52; 

The  corn,  53;    Two  classes  of  plants,  54;  How  plants 

come  up,  55;  Seed  dissemination,  56;  Rest-period  of 

xi 


xii  TABLE  OF  CONTENTS 

PAGES 

seeds,  57;  Storage  of  seeds,  58;  Germination  of  seeds, 
59;  Viability,  60;  External  conditions,  61;  Mois- 
ture, 62;  Oxygen,  63;  Heat,  64;  Media  for  germi- 
nation, 65;  Adulterated  seed,  66;  Special  methods  of 
causing  seeds  to  germinate,  67;  Planting  seeds,  68; 
Time  of  germination,  69;  Transplanting,  70. 

CHAPTER  IV 

ASEXUAL  PROPAGATION  OF  PLANTS  ON  THEIR  OWN  ROOTS      54-68 

Plants  on  their  own  roots,  and  on  the  roots  of  other 
plants,  71;  Layering,  72;  Tip  layering,  73;  Simple 
layering,  74;  Serpentine  or  compound  layering,  75; 
Continuous  layering,  76;  Trench  layering,  77; 
Mound  layering,  78;  Chinese  or  pot  layering,  79; 
Time  for  layering,  80;  Runners,  81;  Cuttings,  82; 
Leaf -cuttings,  83;  Tuber-cuttings,  84;  Root-cuttings, 
85;  Stem-cuttings,  86;  Hardwood  cuttings,  87; 
Best  time  for  making  cuttings,  88;  How  to  make 
hardwood  cuttings,  89;  Cuttings  of  coniferous 
plants,  90;  Softwood  cuttings,  91;  How  to  make 
softwood  cuttings,  92;  Planting  softwood  cuttings,  93; 
Semi-hardwood  cuttings,  94;  Offsets,  95;  Tuberous 
roots,  96;  Tuber,  97;  Bulbs  and  corms,  98;  Media 
for  growth,  99;  Temperature,  100;  Apparatus  for 
growing  cuttings,  101. 

CHAPTER  V 

ASEXUAL  PROPAGATION  ON  THE  ROOTS  OF  OTHER  PLANTS      69-85 

Uses  of  budding  and  grafting,  102;  Limits  of 
grafting  and  budding,  103;  Essential  points  in  graft- 
ing or  budding,  104;  Budding,  105;  Types  of  bud- 
ding, 106;  Shield-budding,  107;  Preparing  the  stock 
previous  to  budding,  108;  Selecting  bud-wood,  109; 
The  operation  of  budding,  110;  Position,  111; 
Budding-knife,  112;  Cutting  the  stock,  113;  In- 
serting the  bud,  114;  Tying,  115;  Removing  the 
ligatures,  116;  Topping  the  budded  trees,  117; 
Other  forms  of  budding,  118;  Flute-,  patch-,  or 
veneer-budding,  119;  Ring-  or  annular-budding, 
120;  H-budding,  121;  Chip-budding,  122;  Fall- 


TABLE  OF  CONTENTS  xiii 

PAGES 

and  June-budding,  123;  Dormant-budding,  124; 
Top-budding,  125.  Grafting:  Parts  of  the  tree  which 
are  grafted,  126;  Grafts  classified  according  to  man- 
ner of  their  making,  127;  Whip-  or  tongue-grafting, 
128;  Cleft-graft,  129;  Kerf-graft  or  inlaying,  130; 
Bark-graft,  131;  Veneer-grafting,  132;  Side-grafting, 
133;  Saddle-grafting,  134;  Inarching  or  approach- 
grafting,  135;  Bridge-grafting,  136;  Grafting  ma- 
terials, 137. 

CHAPTER  VI 

VEGETABLE-GROWING 86-91 

The  soil,  138;  Plowing,  139;  Ordering  and  growing 
seed,  140;  Planting,  141;  Transplanting,  142;  Cul- 
tivating, 143;  Thinning,  144;  Watering,  145;  Dis- 
eases and  insects,  146;  Tools,  147;  Garden  plans, 
148;  Classes  of  vegetables,  149. 

CHAPTER  VII 

ROOT,  TUBER,  AND  BULB  CROPS 92-102 

Root  and  Tuber  Crops:  The  beet,  150;  The  carrot, 
151;  Celeriac,  152;  Chicory,  153;  Horse-radish,  154; 
Jerusalem  artichoke,  155;  The  parsnip,  156;  Irish 
potato,  157;  The  sweet  potato,  158;  Radish,  159; 
Turnips  and  rutabaga,  160.  Bulb  Crops:.  Onion, 
161;  Chives,  162;  Garlic,  163;  The  leek,  164;  The 
shallot,  165. 

CHAPTER  VIII 

CROPS  GROWN  FOR  FOLIAGE  AND  STEMS 103-108 

The  cabbage,  166;  Brussels  sprouts,  167;  Collards 
and  kales,  168;  Cauliflower,  169;  Spinach,  170; 
Other  plants  used  for  greens,  171;  Celery,  172;  Cress, 
173;  Endive,  174;  Lettuce,  175;  Parsley,  176. 

CHAPTER  IX 
CROPS  GROWN  FOR  FRUIT  OR  SEED  PARTS      .     .     .  _ .     .  109-116 

The  legumes,  177;  The  bean,  178;  The  pea,"  179; 
The  soybean  and  cowpea,  180;  The  eggplant,  181; 
Red  peppers,  182;  The  tomato,  183;  Cucurbitous 
crops,  184;  Cucumbers,  185;  Muskmelons,  186; 
Watermelons,  187;  Pumpkins  and  squashes,  188. 


XIV  TABLE  OF  CONTENTS 

CHAPTER  X 

PAGES 
ORCHARD  MANAGEMENT 117-141 

Climate,  189;  Heat,  190;  Cold,  191;  Moisture, 
192;  Air  moisture,  193;  Winds,  194;  Sunshine  and 
light,  195;  Soils,  196;  Selecting  a  location  for  the 
orchard,  197;  Preparation  of  land  for  planting,  198; 
Choosing  the  trees,  199;  Care  of  nursery  stock,  200; 
Laying  out  and  staking  the  orchard,  201;  Orchard 
patterns,  202;  Distance  apart,  203;  Preparing  the 
trees  for  planting,  204;  Trimming  the  roots,  205; 
Planting-board,  206;  Planting  the  tree,  207;  Pruning 
the  top,  208;  The  use  of  fertilizers,  209;  Care  of  the 
trees  the  first  year,  210;  Tillage  of  bearing  orchards, 
211;  Cover-crops,  212;  Inter-cropping,  213;  Fer- 
tilizers, 214;  Nitrogen,  215;  Sources  of  nitrogen,  216; 
Nitrogen  and  cover-crops,  217;  Nitrification,  218; 
Phosphorus,  219;  Potash,  220;  Fertilizers  for  fruits, 
221;  Pruning,  222;  Pruning  young  trees,  223; 
Pruning  trees  of  bearing  age,  224;  Summer  pruning, 
225;  Pruning  tools,  226;  Making  the  cuts,  227; 
Spraying,  228;  Spraying  machinery,  229;  Nozzles 
and  spray-rods,  230;  Kinds  of  sprays,  231;  Thin- 
ning the  fruit,  232;  The  personal  factor,  233. 

CHAPTER  XI 

IRRIGATION  AND  DRAINAGE 142-157 

Recent  irrigation,  234;  Reclamation  service,  235; 
Irrigation  in  humid  regions,  236;  Sources  of  water, 
237;  Diversion  of  streams,  238;  Imperial  Valley, 
239;  Diversion  of  small  streams,  240;  Storage 
reservoirs,  241;  The  underground  water  supply,  242; 
Application  of  water,  243;  Water  measurement,  244; 
Miner's  inch,  245;  Weir  measurement,  246;  Water 
rights,  247;  Moderation  in  irrigation,  248;  Alkali, 
249;  Drainage,  250;  Why  drainage  is  important, 
251;  Drainage  of  swamp  lands,  252;  Drainage  in 
irrigated  regions,  253;  The  necessity  for  irrigation 
and  drainage,  254;  Horticulture  and  irrigation,  255. 


TABLE  OF  CONTENTS  XV 

CHAPTER  XII 

PAGES 

POLLINATION  AND  FERTILIZATION 158-179 

The  flower  and  its  parts,  256;  Pollination  and 
fertilization,  257;  Organs  essential  for  seed  pro- 
duction, 258;  Relation  of  pollination  and  fertili- 
zation to  the  setting  of  fruit,  259;  Requisites  for 
fertilization,  260;  Transportation  of  pollen,  261; 
Ways  to  distinguish  good  from  poor  pollen,  262; 
Viability  of  pollen  affected  by  various  factors,  263; 
Inter-planting  for  pollination,  264;  Artificial  pollina- 
tion, 265;  Procuring  the  pollen,  266;  Storing  the 
pollen,  267;  Emasculating  the  flowers,  268;  Bagging 
the  blossoms,  269;  Applying  the  pollen,  270;  Label- 
ing, 271;  Checks,  272;  Choosing  varieties  for  polli- 
nation purposes,  273;  Requisites  of  good  pollinizer, 
274. 

CHAPTER  XIII 

DECIDUOUS  FRUITS 180-195 

The  apple,  275;  The  pear,  276;  The  quince,  277; 
The  peach,  278;  The  nectarine,  279;  The  apricot, 
280;  Plums  and  prunes,  281;  The  cherry,  282. 
Nuts:  The  almond,  283;  The  walnut,  284;  The 
pecan,  285;  Other  nuts,  286. 

CHAPTER  XIV 

SEMI-TROPICAL  FRUITS 196-205 

Citrus  Fruits:  History,  287;  Frost,  288;  Marketing, 
289;  Insect  pests,  290;  Control  of  insects,  291; 
Citrus  canker,  292;  The  future  of  the  citrus  industry, 
293;  The  pomelo,  294.  The  Olive,  295.  The  Fig,  296. 
Other  semi-tropical  fruits,  297. 

CHAPTER  XV 

SMALL-FRUITS  AND  THE  GRAPE 206-222 

The  Strawberry:  Origin  and  adaptation,  298;  Soils, 
299;  Starting  the  plants,  300;  Planting  systems,  301; 
Cultivation,  302;  Mulching,  303;  Pollination,  304; 
Harvesting  and  packing,  305;  Insects  and  diseases, 
306;  Everbearing  strawberry,  307.  The  Blackberry: 


xvi  TABLE  OF  CONTENTS 

PAGES 

Origin,  308;  Requirements  of  the  blackberry,  309; 
Propagation,  310;  Planting  and  training,  311;  Pol- 
lination, 312;  Cultivation,  313;  Picking  and  shipping, 
314;  Winter  protection,  315;  Special  varieties  of 
blackberries,  316.  The  Raspberry,  317.  Currants 
and  Gooseberries:  Adaptation,  318;  Bearing  habit, 
319;  Cultivation,  320;  Insect  pests  and  diseases, 
321.  The  Grape:  Origin,  322;  The  grape  in  Europe 
and  America,  323;  Origin  of  the  Concord,  324; 
The  grape  industry,  325;  Propagation,  planting, 
and  care,  326;  Grape  pruning,  327;  Spur-pruning, 
328;  Cane-pruning,  329;  Phylloxera,  330;  Other 
insects,  331;  Raisins,  332. 

CHAPTER  XVI 

INSECTS  AND  THEIR  CONTROL 223-245 

The  insect,  333;  Insect  groups,  334;  Metamor- 
phosis, 335;  Some  examples  of  metamorphosis,  336; 
Reasons  for  metamorphosis,  337;  Mouth-parts, 
338;  Importance  of  a  study  of  life  history,  339; 
Control,  340;  Borers,  341;  Apple-tree  leaf-roller,  342; 
Canker-worms,  343;  Red-humped  caterpillar,  344; 
Tent-caterpillar,  345;  Fall  web  worms,  346;  Plum 
curculio,  347;  Plum  gouger,  348;  Scale  insects,  349; 
San  Jose  scale,  350;  Plant-lice,  351;  Mites,  352; 
Control  of  mites,  353;  Blister-mites,  354;  Opportu- 
nities for  insect  study,  355. 

CHAPTER  XVII 

PLANT  DISEASES 246-259 

Causes  of  plant  diseases,  356;  Fungi,  357;  How 
fungi  grow,  358;  Control,  359;  Bacteria,  360; 
Pear-blight,  361;  Powdery  mildew,  362;  Crown- 
gall,  363;  Potato  scab,  364;  Brown-rot,  365;  Shot- 
hole  fungus,  366;  Anthracnose,  367;  Root-rot,  368; 
Damping-off,  369;  Control  of  diseases,  370. 

CHAPTER  XVIII 
MARKET  PREPARATION,  TRANSPORTATION,  AND  STORAGE  .    .  260-277 

Growing  and  marketing,  371;  The  ripening  proc- 
ess, 372;  The  time  for  harvesting,  373;  Decay,  374; 


TABLE  OF  CONTENTS  xvii 

PAGES 

Picking,  375;  Hauling,  376.  Packing-House  Oper- 
ations: Packing,  377;  Wrapping,  378.  Transpor- 
tation and  Storage:  The  railroad,  379;  The  time 
element,  380;  The  temperature  element,  381; 
History  of  refrigeration,  382;  The  refrigerator-car, 
383;  Limitations,  384;  Storage,  385;  Essentials  of 
success  in  cold  storage,  386;  Care  of  storage-rooms, 
387;  Advantage  of  storage,  388. 

CHAPTER  XIX 

MARKETING 278-289 

Commission-men,  389;  The  broker,  390;  The 
jobber,  391;  Sale  by  auction,  392;  Defects  in  the 
marketing  system,  393;  Cooperation,  394;  Essen- 
tials for  success  in  cooperative  marketing,  395;  Bene- 
fits, 396;  Difficulties,  397;  Extent  of  cooperative 
marketing,  398;  An  example  of  cooperative  market- 
ing, 399;  Market  information,  400;  Cost  of  market- 
ing, 401. 

CHAPTER  XX 

INCIDENTAL  PRODUCTS 290-296 

Some  examples  of  by-products,  402;  By-products 
in  horticulture,  403;  Vinegar  manufacture,  404; 
Olive  oil,  405.  Preservation  by  Drying:  Chemical 
changes,  406;  Bacterial  changes,  407;  The  fruit- 
drying  industry,  408;  The  chemistry  of  sulfuring,  409; 
Drying  of  other  fruits,  410;  Effect  of  drying  on  the 
industry,  411. 

CHAPTER  XXI 

THE  USE  OP  ORNAMENTAL  PLANTS 297-310 

The  plan,  412;  The  lawn,  413;  Shrubbery,  414; 
Shrub  planting,  415;  Trees,  416;  Buildings,  417; 
Walks  and  drives,  418;  Straight  lines,  419.  Plant 
Materials:  Climbing  vines,  420;  Boston  ivy,  421; 
Virginia  creeper,  422;  Wisteria,  423;  Shrubs,  424; 
Bridal  wreath,  425;  Viburnum,  426;  Barberry,  427; 
Philadelphus,  428;  Hydrangea,  429;  Trees,  430; 
Lawn  grasses,  431;  Ground  cover,  432.  The  Land- 
scape Plan:  Formal  style,  433;  The  natural  style, 
434. 


LIST  OF  ILLUSTRATIONS 
PLATES  FACING  PAGE 

I.    Propagating  frames 10 

II.    Digging  nursery  stock.  Left-hand  corner,  a  buddei  at  work.       50 

III.  Upper:    Planting  a  tree,  using  a  planting-board.    Lower: 

An  extension  disk,  adapted  to  cultivation  under  branches.       88 

IV.  Upper:     A   type  of  pruning  known   as    " heading  back 

severely."    Lower:   A  tree  pruned  to  laterals     .      .      .     130 
V.    Upper:    Irrigating  a  nursery  by  furrow  system.     Lower: 

Irrigating  orchard  by  basin  system 170 

VI.    Prolific  bearing  of  the  quince 210 

VII.    Upper:    A  thrifty  vineyard  with  orchard  in  background. 
Lower:    Strawberries  grown  in  matted  rows  in  young 

apple  orchard 250 

VIII.    Twig  of  Spircea   Vanhoultei  in   blossom 294 

FIGURES  PAGE 

1.  Showing  how  the  purple  color  is  dominant  and  the  white 

recessive 9 

2.  Plant-cells  of  various  shapes 17 

3.  A,  Diagram  of  a  cell.      B,  A  plasmolyzed  cell     ....  17 

4.  Cell  showing  circulation  of  the  cytoplasm 19 

5.  Chromoplasts  of  various  shapes 20 

6.  Tap-root  of  carrot 21 

7.  Fascicled  roots  of  the  sweet  potato 21 

8.  Tip  of  root  showing  root-cap 22 

9.  Root-hairs  on  young  radish 22 

10.  Root-hair  magnified v 23 

11.  A,  Cross-section  of  very  young  growing  portion  of  exogenous 

stem  with  cells  nearly  alike.    B,  An  older  stem  with  various 
tissues  developing 24 

12.  A  section  of  same  stem  as  in  Fig.  11,  older,  with  vascular 

bundles  closer  together  and  pith  between  compressed  into 
medullary  rays 25 

13.  Cross-section  of  exogenous  stem  showing  annular  rings  of 

wood 26 

14.  Cross-section  of  endogenous  stem  showing  scattered  arrange- 

ment of  vascular  bundles 26 

xix 


xx  LIST  OF  ILLUSTRATIONS 

•**  „ 

FIGURES  PAGE 

15.  Twig  showing  terminal  and  lateral  buds 28 

16.  Peach  twig  showing  habit  of  bearing 28 

17.  Spur  showing  scars  where  apples  have  been  borne      ...  30 

18.  Portion  of  a  cross-section  of  a  leaf  showing  different  cells      .  31 

19.  Diagram  illustrating  functions  of  leaves 32 

20.  The  young  pea  plant 40 

21.  The  bean  seed  ' 41 

22.  Germination  of  pumpkin  seed  showing  peg  catching  and 

removing  testa 42 

23.  Exterior  of  the  flat  surfaces  of  a  kernel  of  corn     ....  42 

24.  Longitudinal  section  of  a  kernel  of  corn 43 

25.  Bean  coming  through  the  ground,  the  cotyledons  being  pulled 

out 44 

26.  Stratification  of  seeds  in  box 45 

27.  Tip  layer,  showing  early  growth  of  tip 55 

28.  A  simple  layer 55 

29.  Serpentine  layer 55 

30.  Continuous  layer 56 

31.  Mound  layer 56 

32.  Callusing  of  cuttings 58 

33.  A  leaf-cutting 58 

34.  Root-cutting  of  the  blackberry 59 

35.  Hardwood  cutting  of  the  currant 60 

36.  Single-eye  cutting  of  the  grape 61 

37.  Softwood  cutting  of  the  carnation 62 

38.  Corm  of  gladiolus  growing  about  old  corm .64 

39.  A  simple  propagating  oven 66 

40.  Method  of  planting  cuttings  in  a  trench 66 

41.  A  budding-knife 73 

42.  Making  the  longitudinal  incision  preparatory  to  budding      .  73 

43.  Making  the  cross-cut  of  the  "T"  with  a  rolling  motion  of  the 

knife 74 

44.  Cutting  the  bud 74 

45.  Inserting  the  bud 75 

46.  The  bud  inserted 75 

47.  The  bud  tied  with  string 75 

48.  Twig-bud  cut  ready  for  insertion 76 

49.  Patch-budding ....*.  76 

50.  H-budding ..........  76 

51.  Chip-budding  .      .      . 76 

52.  Whip-grafting 79 


LIST  OF  ILLUSTRATIONS  xxi 

FIGURES  PAGE 

53.  Splitting  the  stock  with  the  grafting  tool  which  is  driven  in 

with  a  wooden  mallet 79 

54.  Opening  the  cleft  for  the  insertion  of  the  cions     ....  80 

55.  Cions  cut  for  insertion  in  the  cleft 80 

56.  Cions  inserted  in  cleft  ready  for  waxing 80 

57.  The  graft  after  being  waxed 81 

58.  Bark-graft,  showing  the  method  of  cutting  cions  and  inserting 

in  stock 81 

59.  Side-graft 82 

60.  Bridge-graft  showing  cions  inserted 82 

61.  An  uncongenial  graft  union 84 

62.  A  dibber 90 

63.  Chard  beet 92 

64.  Celeriac,  untrimmed  root  and  root  trimmed  for  market     .  94 

65.  Chicory  root 94 

66.  Root  of  horse-radish   .    ' 94 

67.  Onion  in  flower .,     .  100 

68.  Top  onion,  one  kind  of  "sets" 100 

69.  Chives 102 

70.  Leek 102 

71.  Wild  cabbage  plant  in  seed  on  chalk  cliffs  of  England     .      .  103 

72.  The  Savoy  cabbage "      .  104 

73.  Brussels  sprouts 105 

74.  Kale 105 

75.  Head  of  cauliflower 105 

76.  Celery  banked  with  earth 107 

77.  Endive        107 

78.  Leaf  type  of  lettuce 108 

79.  Head  type  of  lettuce 108 

80.  The  soybean Ill 

81.  Eggplant Ill 

82.  Pepper 112 

83.  Tomato  trained  on  a  stake 112 

84.  Field  pumpkin 115 

85.  Square  system  of  orchard  planting         124 

86.  Quincunx  system  of  orchard  planting 124 

87.  Hexagonal    or    equilateral    triangular    system    of    orchard 

planting 125 

88.  Showing  where  to  cut  tree  back  to  whip  after  planting     .      .  127 

89.  Nodules  on  roots  of  legume 129 

90.  A  one-year-old  apple  tree  before  pruning    ......  135 


xxii  LIST  OF  ILLUSTRATIONS 

FIGURES  PAGE 

91.  The  apple  tree  in  Fig.  90  after  pruning 136 

92.  Pruning  saw 136 

93.  Folding  pruning  saw 137 

94.  Pruning  saw 137 

95.  Pruning  shears 137 

96.  Pruning  shears ' 137 

97.  Pruning  shears 138 

98.  Showing  construction  of  Cippoletti  weir 150 

99.  Cherry  blossom 158 

100.  Fertilization 160 

101.  Multiplication  of  cells  after  fertilization 161 

102.  Pistil  of  walnut,  showing  large  stigma 161 

103.  Pollen-grains 162 

104.  Pollen-grains  of  the  Drake  almond 163 

105.  Showing  Van  Teighem  cell  with  pollen-grains  mounted  for 

examination  under  a  binocular  microscope     .      ...  166 

106.  Germination  of  Black  Heart  sweet  cherry  pollen  ....  167 

107.  Photomicrograph   of   California  almond  pollen-grains   ger- 

minating   167 

108.  Position  of  the  fingers  for  emasculating 173 

109.  Cutting  through  the  calyx  with  the  finger-nails     ....  173 

110.  The  perianth  removed ."    ;      .      .      .  174 

111.  One  of  the  parent  Washington  Navel  orange  trees  still  grow- 

ing in  Riverside,  California 197 

112.  Proper  depth  to  set  strawberry  plants         207 

113.  A  grape-vine  pruned  and  tied  to  the  long-cane  system     .      .  217 

114.  Unit  of  short  pruning  the  grape 218 

115.  Unit  of  long  pruning  the  grape 219 

116.  The  codlin-moth,  showing  stages  in  life  history     ....  228 

117.  Larva  of  flat-headed  borer 230 

118.  Adult  of  flat-headed  borer 230 

119.  The  plum  curculio 235 

120.  The  plum  gouger  and  its  work 236 

121.  Scale  insects — three  mature  Citricola  and  one  black  scale  237 

122.  A  parasitized  larva 239 

123.  The  Eyed  Ladybird  and  Ash-Gray  Ladybird,  predaceous  on 

aphids;  the  Black  Ladybird  predaceous  on  black  scale;  the 

Mealy  Bug  destroyer 239 

124.  Aphids  or  plant-lice 240 

125.  Red-spider 240 

126.  A  fungus,  showing  spores       . 248 


LIST  OF  ILLUSTRATIONS  xxiii 

FIGURES  PAGE 

127.  Pear-blight 250 

128.  Crown-gall 252 

129.  Potato  scab 253 

130.  Shot-hole  fungus 255 

131.  Apple  bitter-rot 257 

132.  Peach-yellows 257 

133.  Peach-rosette 258 

134.  Steps  in  distribution  of  fruit  by  the  California  Fruit  Growers' 

Exchange 286 

135.  Distribution  of  gross  proceeds  of  citrus  sales     ....     288 


HORTICULTURE  FOR  SCHOOLS 


HORTICULTURE  FOR  SCHOOLS 

CHAPTER    I 
HORTICULTURE  AND  PLANT  IMPROVEMENT 

THE  word  "horticulture"  is  derived  from  two  Latin  words, 
hortus  and  cultura.  The  first  of  these  means  a  garden, 
originally  in  the  Greek  an  inclosed  space  for  plants;  the 
second  signifies  care  or  cultivation.  Literally,  therefore,  the 
combination  suggests  the  care  of  a  small  inclosed  area. 
However,  the  conditions  of  life  change  from  generation  to 
generation,  and  the  meanings  of  words  change  also.  Horti- 
culture is  now  not  a  question  of  inclosures,  or  even  of  gardens. 
The  original  significance  of  the  derivative  is  as  out-of-date 
as  is  the  wooden  plow  of  the  Romans. 

1.  Horticulture  defined. — Horticulture  is  the  growing  of 
flowers,  fruits,  vegetables,  and  ornamental  trees  and  shrubs. 
In  the  aggregate,  it  is  an  industry  which  engages  the  atten- 
tion of  a  great  many  persons  and  which  represents  the  outlay 
of  large  amounts  of  capital.     From  the  limited  beginnings 
connoted  by  the  Latin  roots,  it  has  grown,  in  America,  to 
the  proportions  of  a  business  of  great  magnitude  and  has 
become  a  major  affair  in  the  agriculture  of  the  country.    In 
Europe,  floriculture,  or  the  raising  of  flowers,  has  received 
much  attention  for  a  long  period.     In  America,  fruit-  and 
vegetable-growing  have  been  especially  emphasized,  but  orna- 
mental gardening  is  gradually  acquiring  importance. 

2.  Plant  material. — A  brief  investigation  will  show  that 
many  varieties  of  cultivated  plants  are  grown.    Of  the  apple 
alone,  most  popular  and  widespread  of  all  our  fruits,  there 

3 


4  HORTICULTURE  FOR  SCHOOLS 

are  more  than  one  thousand  varieties.  Of  the  grape  there 
are  twice  as  many.  Of  peaches,  more  than  two  thousand 
varieties  have  been  listed  in  the  state  of  New  York  alone. 
There  are  many  thousands  of  varieties  of  fruits  and  vege- 
tables. The  thoughtful  student  will  at  once  wonder  at  this 
multiplicity  of  varieties.  Whence  have  they  all  come?  What 
purpose  do  they  serve?  Of  what  concern  are  they  to  the 
student  of  horticulture? 

3.  Varieties  not  permanent. — An  historical  study  likewise 
reveals  some  interesting  facts.     Of  the  varieties  of  apples 
known  two  hundred  years  ago,  only  a  few  are  found  in  the 
orchards  of  today.    A  variety  has  its  period  of  popularity, 
being  in  time  replaced  by  new  sorts  which  fill  new  needs 
and    thrive    better  under  new   conditions.      Sometimes  a 
form  like  the  Newtown  Pippin  apple  or  the  Concord  grape 
remains  for  many  years  a  standard,  but  these  outstanding 
exceptions  tend  only  to   emphasize  the  general  rule,  that 
new  varieties  are  constantly  appearing  and   old   ones  are 
passing. 

4.  Change  is  universal. — This  phenomenon  of  change  is 
not  limited  to  varieties  of  fruits.    John  Muir,  in  Our  National 
Parks,  expresses  this  universal  law  of  life.    "Nature  is  ever 
at  work  building  and  pulling  down,  creating  and  destroying, 
keeping  everything  whirling  and  flowing,  allowing  no  rest  but 
in  rhythmical  motion;    chasing  everything  in  endless  song 
out  of  one  beautiful  form  into  another."     He  was  thinking, 
when  he  wrote,  of  forests  and  meadows,  of  glaciers  and 
streams,  of  what  we  are  pleased  to  call  "the  everlasting 
mountains";  but  his  words  are  equally  true  of  the  cultivated 
forms  of  plants. 

5.  The  nightshade  family. — The  nightshades  illustrate  the 
variety  in  form  that  plants  exhibit  and  the  way  in  which  man 
has  availed  himself  of  this  variety  in  search  of  food.     The 
common  black  nightshade  grows  wild  in  all  parts  of  the 
United  States.    With  its  small  white  or  violet  colored  bios- 


HORTICULTURE  AND  PLANT  IMPROVEMENT  5 

soms,  and  its  fruits  shading  from  green  to  black,  it  is  found 
along  roadsides  and  in  uncultivated  corners  everywhere.  It 
occurs  in  many  forms.  One  species  is  very  poisonous 
and  bears  the  name  "deadly  nightshade"  or  more  properly 
belladonna;  it  is  not  wild  in  North  America,  but  many  of 
the  species  found  here  contain  drugs  of  greater  or  less  toxic 
effect.  There  are  many  species  of  Solanum,  which  is  the 
principal  genus  of  the  nightshade  family.  Solanum  nigrum, 
variously  known  as  black  nightshade,  stubbleberry,  or  garden 
huckleberry,  and  Solanum  carolinense  (the  horse  nettle)  are 
two  well-known  plants  of  the  genus;  there  are  many  kinds 
known  as  weeds,  others  as  greenhouse  ornamentals,  and  the 
eggplant  and  red  pepper  are  also  of  this  genus. 

The  botanical  divisions  of  plants  require  some  explanation.  Plants 
are  grouped  into  large  divisions  known  as  families.  Each  family 
contains  all  those  plants  having  a  certain  number  of  characteristics 
in  common.  For  example,  the  nightshade  family,  Solanacese,  includes 
all  plants  having  the  following  characteristics:  Herbs  or  shrubs  with 
colorless  juice,  and  alternate  leaves  without  stipules.  Flowers  regular 
with  parts  in  fives.  Corolla  with  parts  overlapping  or  touching  by 
contiguous  edges  in  the  bud.  Ovary  usually  2-celled.  Style  single. 
Fruit  a  many  seeded  berry  or  capsule.  Foliage  strongly  scented.  Fruits 
often  poisonous,  but  some  are  edible. 

Families  are  again  divided  into  groups  called  genera.  For  example, 
the  genus  Solanum  includes  those  plants  in  the  nightshade  family 
having  the  following  characteristics  among  others:  Corolla  wheel- 
shaped,  5-parted  or  cleft.  Stamens  with  short  filaments  and  long 
anthers,  which  often  apparently  unite  around  the  style.  Fruit  usually 
a  berry. 

The  genera  are  again  divided  into  still  smaller  divisions  called  species. 
For  example,  the  species  name  "tuberosum"  refers  to  the  potato, 
belonging  to  the  genus  "Solanum,"  of  the  Solafl&cese,  and  the  botanist 
writes  the  name  of  the  potato  Solanum  tuberosum,  giving  the  genus 
name  followed  by  the  species  name,  capitalizing  the  genus  name  only 
(when  the  species  name  is  that  of  a  person  or  a  country,  it  may 
be  capitalized).  Following  are  the  characteristics  of  this  species: 
A  perennial  with  underground  tubers  by  which  it  propagates  itself 
asexually.  Low-growing,  much  branched  herbaceous  tops.  Leaves 
unequally  pinnate.  Flowers  in  clusters,  variable  in  color — white,  blue, 


6  HORTICULTURE  FOR  SCHOOLS 

violet,  purple.  Fruit  a  berry  but  usually  lacking  in  this  country  due 
to  the  deficiency  of  viable  pollen.  This  species  fruits  abundantly  in 
South  America,  where  it  is  native. 

6.  The  potato  belongs  to  the  nightshade  family.     Its 
botanical  name  is   Solanum   tuber osum.     The   resemblance 
between  the  potato  and  other  nightshade  plants  is  not  ob- 
vious at  first  sight ;   but  even  a  casual  examination  of  their 
flowers  and  fruits  reveals  many  similarities.    There  is  differ- 
ence as  to  size,  to  be  sure ;  but  in  structure  they  resemble  each 
other  very  closely.     The  fruits  of  all  the  nightshades  are 
strikingly  similar.    The  potato  does  not  bear  fruits  very  often ; 
the  pollen  is  usually  not  viable  in  North  America.    Occasion- 
ally, however,  the  green  fruits  may  be  seen  on  the  potato  vine. 
While  not  edible,  they  nevertheless  are  comparable  with  the 
tomato,  both  being  seed-bearing  berries.    The  fruits  or  berries 
of  the  potato  are  much  larger  than  those  of  the  common 
nightshade,  but  here  again  an  examination  of  the  structure 
of  each  will  show  how  close  is  the  resemblance  between  them. 

7.  Inter-grafting. — It  is  possible  to  graft  a  tomato  on  a 
potato,  or  a  tomato  on  the  common  nightshade.    Of  course, 
the  graft  is  of  no  commercial  importance,  and  is  of  signifi- 
cance only  in  a  scientific  sense.    But  it  illustrates  in  a  graphic 
way  the  close  relationship  between  the  potato,  the  tomato, 
and  the  nightshade,  all  regarded  by  some  authors  as  species 
of  the  genus  Solanum. 

8.  Domestication. — All  cultivated  plants  came  originally 
from  the  wild,  directly  or  indirectly.     Some  of  them  were 
brought  under  domestication  so  many  centuries  ago  that 
there  is  no  definite  pcord  of  the  date  or  process.    Some,  such 
as  rice  and  the  grape,  were  under  the  care  of  man  before  the 
advent  of  written  history,  and  the  early  beginnings  of  domesti- 
cation are,  therefore,  shrouded  in  the  haze  of  the  distant  past. 

We  know,  however,  the  broad  outlines  of  the  narrative, 
uncertain  though  its  beginnings  are ;  and  we  can  pick  out  the 
different  threads  and  follow  each,  step  by  step.  We  know 


HORTICULTURE  AND  PLANT  IMPROVEMENT          7 

also  that  the  story  is  not  yet  complete,  but  that  even  today 
the  process  of  domestication  and  of  plant  improvement  is 
going  on. 

There  is  a  division  of  the  Bureau  of  Plant  Industry  of  the 
United  States  Department  of  Agriculture  known  as  the 
Division  of  Foreign  Plant  and  Seed  Introduction,  whose  work 
it  is  to  search  for  new  and  promising  plants  the  world  over. 
The  interior  of  China,  the  wilds  of  Africa,  the  continent  of 
South  America  have  all  yielded  new  forms  to  our  list  of  culti- 
vated plants.  No  corner  of  the  globe  is  so  inaccessible  or  so 
remote  as  to  escape  the  vigilance  of  the  explorers  for  new 
plant  material. 

9.  American  wild  plants. — America  has  contributed  many 
plants  to  the  horticulture  of  the  world.     The  origin  of  the 
Concord  grape  is  narrated  in  a  later  chapter.     The  native 
plums,  apples,  and  berries  have  been  drawn  on  largely  for 
new  and  better  varieties  and  as  yet  the  possibilities  have  not 
been  exhausted.     The  conditions  in  America  are  different 
from  those  existing  in  the  Old  World;   and  plant  forms  are 
being  developed  to  meet  the  needs  of  the  continent. 

THE  PROCESS  OF  IMPROVEMENT 

The  question  arises:  Is  plant  improvement  a  matter  of 
chance,  or  can  it  be  controlled  by  man?  Does  nature  work 
blindly  to  produce  better  forms,  or  may  the  intelligence  of  the 
skilled  manipulator  and  student  have  an  influence  in  it? 
Fortunately  for  the  horticulturist,  the  work  of  plant  improve- 
ment can  be  controlled  and  directed  to  a  large  degree  by  skill 
and  study;  and  chance  and  "luck"  play  a  part  the  impor- 
tance of  which  is  constantly  diminishing  as  time  goes  on. 

10.  Darwin. — The  studies  of  Charles  Darwin  mark  the 
greatest  contribution  made  in  the  nineteenth  century  to  the 
subject  of  origins,  and  of  variation  in  plants  and  animals. 
Darwin  was  born  at  Shrewsbury,  England,, February  12th, 
1809.    This  same  year  marked  the  birth  of  two  other  great 


8  HORTICULTURE  FOR  SCHOOLS 

characters  of  English  history,  Gladstone  and  Tennyson. 
Darwin's  birthday,  it  will  be  noticed,  is  the  same  as  that  of 
Abraham  Lincoln. 

11.  The  origin  of  species. — Darwin  was  not  alone  in  the 
discovery  of  the  fact  that  the  forms  of  plant  and  animal  life 
are  subject  to  variation;  but  he  studied  the  matter  so  pains- 
takingly, and  wrote  so  convincingly,  that  his  writings  have 
profoundly  influenced  all  scientific  thought  since  his  time. 
His  great  book,  The  Origin  of  Species,  was  published  in  1859. 
In  it  he  points  out  that  the  forms  of  life  are  constantly  under- 
going minute  changes;   that  these  changes  may  be  so  small 
at  the  time  as  to  be  scarcely  perceptible,  but  that  in  the  course 
of  centuries  they  become  sufficiently  great  to  make  the 
differences  recognizable.    For  example,  if  a  hundred  seeds  are 
planted  from  one  parent  plant,  no  two  of  these  seedlings  will 
be  alike;  and  some  will  be  better  able  to  meet  the  conditions 
of  life  than  will  their  fellows.    They  will  tend  to  persist,  and 
to  transmit  these  differences  to  their  offspring;  and  the  other 
forms  will  tend  to  perish.    The  process  is  so  slow  as  to  escape 
observation;  but  in  the  course  of  many  centuries  the  forms 
of  plants  and  animals  will  gradually  change.    This,  in  essence, 
is  Darwin's  theory  of  evolution  by  means  of  natural  selection. 
It  is  now  recognized  by  scientific  men  everywhere  as  one  of 
the  fundamental  hypotheses  to  account  for  the  forms  of  life. 

12.  Mendel. — Gregor  Johann  Mendel,  an  Austrian  monk, 
was  born  in  1822  and  died  sixty-two  years  later.    He  con- 
ducted experiments  in  the  crossing  of  plants,  publishing  his 
results  in  1865  in  a  paper  under  the  title  "Studies  in  Plant 
Hybridization."     This  paper  attracted  no  attention  in  the 
scientific  world  when  it  was  written,  and  subsequently  re- 
mained unnoticed  until  1900,  sixteen  years  after  the  author's 
death.    The  discoverers  of  the  paper  recognized  at  once  that 
it  contained  a  fundamental  law  of  heredity ;  and  the  researches 
of  the  obscure  Austrian  monk  are  now  known  to  students  of 
natural  science  everywhere. 


HORTICULTURE  AND   PLANT   IMPROVEMENT 


9 


13.  Mendel's  law. — Mendel  worked  with  the  ordinary 
garden  pea.  He  noted  that  there  are  easily  recognized 
differences  in  different  varieties.  The  peas  of  some  varieties 
are  wrinkled,  while  others  are  smooth.  Some  flowers  are 
purple,  while  others  are  red  or  white.  The  vine  is  dwarf  in 
some  varieties  and  tall  in  others. 

He  chose  one  set  of  contrasting  characters  and  experi- 
mented with  that.  For  example,  he  crossed  a  purple  with  a 
white-flowered  variety.  When  the  seed  produced  by  this 
cross  was  planted,  a  vine  with  purple  flowers  resulted.  But 
the  plants  of  the  generation  following  this  hybridization  did 
not  all  produce  purple  flowers.  Indeed,  one  fourth  of  the 
plants  of  this  second  generation  gave  white  flowers.  The 
remaining  three-fourths  produced  purple  flowers.  The  white 
remained  white  through  succeeding  generations.  One-third 
of  the  purple  remained  purple  through  succeeding  genera- 
tions. Two-thirds  of  the  purple  were  indeterminate,  breaking 
up  in  succeeding  generations  in  the  proportion  of  one-fourth 
pure  white,  one-fourth  pure  purple  and  one-half  indeterminate. 
The  following  diagram  (Fig.  1)  shows  how  the  purple  color  is 
controlling  or  dominant  and  the  white  not  controlling  or 
recessive,  the  numbers  indicating  proportions : 


PURPLE  PEAS  CROSSED 
WITH  WHITE  PEAS 


S/PST.  2ND.  3/?D.  4TM  5TH. 

GENERATION  GENERATION  GENERATION  GENERATION  GENERATION  GENERATION 


7  purpfe-*-  purp/p-*-  fit/rp/e-*  fourp/p-*- 
'!  purpfe-*-  fiurfifc  —  *-  purpfe^*- 

"1  purfife  —  *-  pusyj/e^*-  purpte 
'ffiwpte  —  *•  jbi/rpfe 


2  fit/tir/d 


2  hybrid 


J  white  — -  white 

1  white  — *•   white  -*-  white 

J  white  — ^  white  — •-  white  — *•  white 

2  white  — ^   white  — *•   white  '—+-   white  -+-  white 

FIQ.  1. — Showing  how  the  purple  color  ia  dominant  and  the  white  recessive. 


10  HORTICULTURE  FOR  SCHOOLS 

14.  Dominant  and  recessive  characters. — The  white  char- 
acter in  the  above  illustration  disappeared  in  the  first  hybrid 
generation,  and  reappeared  in  succeeding  generations.    It  is, 
therefore,  said  to  be  a  recessive  character,  while  the  purple  is 
spoken  of  as  dominant.    This  behavior  of  characters  is  not 
confined  to  colors  of  blossoms  of  the  pea.    It  is  a  fundamental 
consideration  in  all  plant  improvement  through  hybridization. 

15.  De  Vries.— Hugo  de  Vries  (born  1848),  a  Dutch  bota- 
nist, was  one  of  the  discoverers  in  1900  of  Mendel's  epoch- 
making  treatise  on  hybridization.    De  Vries  became  professor 
of  plant  anatomy  and  physiology  at  the  University  of  Amster- 
dam, in  Holland,  in  1878.    His  many  important  contributions 
to  the  study  of  plant-breeding  have  stimulated  some  of  the 
most  important  investigations  since  Darwin. 

16.  The  mutation  theory. — With  the  name  of  de  Vries  is 
associated  the  " theory  of  mutation,"  first  set  forth  by  him  in 
a  book  with  that  title  in  1901.    Darwin  thought  that  changes 
are  gradual,  almost  imperceptible,  but  that  any  change,  no 
matter  how  slight,  may  give  a  plant  an  advantage  which 
would  enable  it  to  survive  in  larger  numbers  than  its  less 
fortunate  neighbors.    De  Vries  proved  by  experimental  evi- 
dence that  sometimes  changes  occur,  not  gradually,   but 
suddenly,  or  "by  jumps."  These  changes  are  called  mutations. 

These  mutations  are  manifest  in  many  forms.  They  have 
been  observed  in  the  case  of  beans  as  a  change  in  the  shape 
of  the  seed  or  as  an  increase  in  the  plant's  resistance  to 
frost.  On  peach  trees,  branches  have  developed  which  bore 
nectarines.  In  carnations  and  chrysanthemums,  as  in  many 
other  garden  plants,  sports  are  often  found.  Sometimes 
these  mutations  give  rise  to  forms  useful  to  man,  some- 
times the  reverse.  They  constitute  one  of  the  factors  which 
must  be  taken  into  account  in  any  consideration  of  plant 
improvement. 

17.  Plant    improvement    a    division    of    science. — The 
subject  of  plant  improvement  is  so  important  that  it  is  re- 


HORTICULTURE  AND  PLANT  IMPROVEMENT         11 

ceiving  much  attention.  Throughout  the  country  the  experi- 
ment stations  are  working  on  the  problem.  They  are  con- 
ducting investigations  with  old  varieties,  in  attempts  to  im- 
prove them:  and  they  are  working  for  new  varieties,  with  the 
expectation  of  making  contributions  of  value  to  growers. 
Nurserymen  recognize  the  importance  of  the  work.  The 
researches  of  Mendel,  de  Vries,  and  others  have  indicated  the 
path  which  the  plant-breeder  who  is  to  achieve  success  must 
follow. 

18.  Hybridization. — When  plants  are  crossed,  new  forms 
may  result.     The  seed  carries  the  characteristics  of  two 
parent  plants,  that  which  furnished  the  pollen,  and  that 
which  bore  the  seed.    The  parents  may  have  been  unlike  in 
one  or  more  particulars,  and  the  new  seed  may  be  dissimilar 
from  either  of  them.    The  different  characters  may  compose 
or  blend  in  varying  ways. 

19.  One  effect  of  hybridization. — The  crossing  of  plants 
has  the  effect  of  disturbing  the  type,  with  the  result  that  new 
forms  are  likely  to  appear.    These  may  be  desirable  to  man, 
or  of  no  importance.     If  desirable,  the  new  form  may  be 
propagated  at  once  by  budding,  grafting,  cuttings,  or  other 
asexual  means.     If  the  plant  is  propagated  by  seed,  the 
progeny  must  be  selected,  year  after  year,  until  the  form  comes 
true  to  type.    This  may  require  many  generations  of  plants 
and  hundreds  or  even  thousands  of  individuals.    The  process 
is  slow,  laborious,  and  expensive;  but  it  is  one  of  the  essen- 
tials in  good  plant-breeding. 

20.  Bud-selection. — The  method  of  plant  improvement 
known  as  bud-selection  has  received  much  attention  in  recent 
years.    The  term  indicates  the  process  of  choosing  buds  for 
propagation  from  trees  of  known  character.    Its  effectiveness 
in  the  case  of  all  varieties  of  fruits  is  a  matter  of  question  at 
present.    Results  with  apples,  for  example,  have  been  both 
negative  and  positive.    Other  fruits,  such  as  the  Washington 
Navel  orange,  are  much  more  given  to  the  formation  of  bud 


12  HORTICULTURE  FOR  SCHOOLS 

mutations,  and  bud-selection  is  useful  not  alone  for  the  pur- 
pose of  perpetuating  more  desirable  forms,  but  also  of  avoid- 
ing the  use  of  those  that  are  less  desirable.  It  is  supposed  to 
be  specially  efficacious  in  promoting  productivity. 

21.  Ways  in  which  plants  vary. — Sometimes  plants  may 
be  made  to  vary  with  regard  to  chemical  contents  of  root, 
stem,  leaf,  or  fruit.  An  excellent  example  is  afforded  by  the 
sugar-beet,  which,  in  the  course  of  twenty-five  years,  was  so 
changed  by  breeding  and  selection  that  the  average  sugar- 
content  was  raised  from  6  to  15  per  cent,  and  in  exceptional 
cases,  as  high  as  22  or  23  per  cent.  Another  example  of  such 
variation  is  the  changing  of  the  proportion  of  protein  to 
starch  in  Indian  corn.  In  the  corn  used  for  the  manufac- 
ture of  corn-starch,  the  starch-content  of  the  grain  has  been 
increased  materially,  and  the  protein-content  decreased.  Still 
another  example  is  the  increase  in  the  proportion  of  sugar  in 
plums;  the  prune  is  a  plum  in  all  respects  except  that  it 
has  sufficient  sugar  to  enable  it  to  be  dried  without  remov- 
ing the  pit.  This  addition  of  sugar  has  been  secured  by 
means  of  selection  with  regard  to  sugar-content  through 
a  long  period  of  years.  Plants  may  be  improved  in  respect 
to  the  size  of  their  fruits.  The  wild  crab  is  very  small 
in  comparison  with  the  cultivated  apple.  Varieties  of 
blackberries  produce  fruits  differing  greatly  in  size.  The 
same  is  true  of  the  tomato  and  many  other  cultivated 
plants. 

Again,  plants  may  be  made  to  change  with  respect  to  their 
resistance  to  frost  and  the  time  of  ripening  of  the  fruits. 
Bailey  states  that  apples  not  suited  to  our  northern  climate 
have  been  changed  by  crossing  with  Siberian  crab-apples 
so  that  the  area  adapted  to  apple-growing  has  been  extended 
northward.  The  peach  is  particularly  susceptible  to  frost- 
injury;  yet  it  is  grown  successfully  today  on  both  the  Ameri- 
can and  Canadian  side  of  the  Great  Lakes,  as  well  as  in  Nova 
Scotia.  This  is  largely  the  result  of  the  securing  of  varieties 


HORTICULTURE  AND  PLANT  IMPROVEMENT        13 

better  adapted  to  the  rigors  or  the  shorter  seasons  of  these 
northern  localities. 

22.  Life  forms  not  fixed. — In  many  other  ways  plants  are 
varying  constantly.    It  must  ever  be  borne  in  mind  that  the 
forms  of  life  are  not  fixed,  that  all  forms  are  to  a  certain 
degree  plastic,  and  that  within  certain  limits  they  can  be 
changed  by  the  efforts  of  skilled  manipulators.    The  improve- 
ment of  plants  is  one  of  the  great  and  interesting  problems 
of  horticulture. 

23.  Modern  conditions  demand  the  best. — A  merchant 
must  have  on  his  shelves  an  up-to-date  stock  if  he  is  to  com- 
pete on  successful  terms  with  progressive  rivals.    A  railroad 
company  must  look  to  the  condition  of  its  engines  and  cars 
and  buildings.    The  horticulturist  is  also  a  business  man,  and 
his  stock  in  trade  is  the  plants  he  cultivates.    He  will  take 
risks,  as  does  every  other  business  man.    He  will  have  disease 
to  combat,   and   insect   pests  to   control,  irrigation   ques- 
tions to  solve,  and  problems  of  every  sort  to  face.    Com- 
petition  has  always  been   keen,   and   is   keen  today.     It 
is  essential,  therefore,  that  his  stock  be  up-to-date,  that 
his  trees  and  plants  represent  the  best  that  can  possibly  be 
secured. 

24.  The  goal. — The  possibilities  of  plant  improvement 
are  so  great  that  no  matter  how  much  has  been  accomplished 
or  how  much  may  yet  be  undertaken,  the  goal  will  always  be 
ahead.     There  is  plenty  of  room  for  achievement.     Plant 
improvement  is  of  vast  importance  to  the  human  race.    To 
the  individual  horticulturist  and  the  scientist,  it  opens  an 
inspiring  field  for  his  endeavor. 

The  elements  in  practical  plant-breeding  are  these:  (1)  to 
produce  or  discover  a  desirable  variation;  (2)  to  stabilize 
and  perhaps  to  improve  the  variation  by  continued  selection. 
The  operator  should  understand  the  laws  of  heredity,  that 
he  may  know  what  is  possible  of  accomplishment  and  thereby 
direct  his  effort  intelligently. 


14  •  HORTICULTURE  FOR  SCHOOLS 

EXERCISES 

EXEECISE  I. — Wild  and  domesticated  forms. 

Materials. — Mature  specimens  of  the  following  plants  showing 
roots,  stems,  leaves,  flowers,  and  fruit:  Tomato,  potato,  nightshade. 

Procedure. — Note  the  general  appearance  of  these  different  plants. 
Does  a  superficial  examination  reveal  any  similarities?  Compare 
closely  the  leaf  of  the  potato  with  that  of  the  tomato  and  the  night- 
shade. Point  out  all  the  similarities  and  all  the  differences  that  you 
can  detect.  Do  the  same  with  the  flowers  of  the  three  plants,  examining 
the  structure  of  the  flowers  in  some  detail.  Count  the  sepals,  petals, 
and  stamens  of  each.  Note  the  form  of  the  corolla  in  each  case.  Does 
this  suggest  any  relationship  existing  between  the  different  plants? 

It  may  be  difficult  to  find  a  potato  fruit,  but  if  possible  secure  one 
and  compare  it  with  the  fruit  of  the  tomato  and  of  the  nightshade. 
What  evidence  is  there  here  of  similarity  of  structure?  Why  is  it  that 
the  potato  is  grown  for  its  tubers  while  the  tomato  is  grown  for  its 
fruit?  The  structure  shows  that  they  have  a  close  botanical  relationship. 
The  potato  and  tomato  are  indigenous  to  the  Americas,  while  some 
form  of  the  nightshade  is  found  in  widely  separated  parts  of  the  world. 
A  study  of  the  history  of  the  tomato  shows  that  a  hundred  years  ago 
it  was  regarded  as  poisonous  and  this  prejudice  against  it  disappeared 
only  recently.  The  present  cultivated  forms  are  also  a  very  recent 
development. 

Do  you  think  it  would  be  possible  to  make  such  improvements  in 
the  nightshade  as  have  been  brought  about  in  the  tomato?  Explain 
fully  the  reasons  which  lead  you  to  your  conclusion. 

Why  does  the  potato  not  bear  fruit  as  does  the  tomato?  Do  you 
think  it  would  ever  be  possible  to  secure  a  potato  which  would  bear 
fruit  regularly?  If  so,  how  could  this  be  accomplished?  Would  there 
be  any  advantage  in  having  such  a  potato? 

EXERCISE  II. 

Materials. — Wild  forms  native  to  the  student's  locality. 

Procedure. — Bring  to  class  samples,  including,  if  possible,  fruit  of 
any  plants  growing  wild  in  your  locality  which  are  closely  related  to 
cultivated  forms.  For  example:  In  many  parts  of  the  United  States 
there  can  be  found  wild  cherries,  plums,  grapes,  strawberries,  crab- 
apples,  or  other  plants.  Are  these  specimens  which  you  have  brought 
truly  wild  or  are  they  feral?  Explain  the  difference  between  the  two 
terms.  Are  these  specimens  superior  in  any  way  to  the  cultivated 
forms?  (In  answering  this  question  think  of  their  resistance  to  disease, 


HORTICULTURE  AND  PLANT  IMPROVEMENT         15 

their  tendency  toward  fruitfulness,   their  flavor,   size,   resistance  to 
insect  pests,  susceptibility  to  frost). 

If  in  a  region  where  members  of  the  huckleberry,  cranberry,  or 
blueberry  family  are  found  bring  in  specimens  of  these  plants.  Do 
you  consider  them  wild  or  domesticated?  Where  did  they  originate? 
Is  there  any  possibility  of  improvement  in  the  future?  If  so,  along 
what  lines? 

EXERCISE  III. — Project  study. 

Procedure. — The  student  should  report  in  class  concerning  the  type 
of  project  which  he  plans  to  take  up  during  the  school  year.  He  should 
also  discuss  at  this  time  the  connection  between  plant  improvement 
and  the  crop  that  he  is  growing.  If  it  is  an  annual,  he  should  take  up  the 
matter  of  seed  selection  and  should  get  all  the  information  he  can  from 
books  or  from  publications  of  experiment  stations  concerning  the 
work  that  has  been  done  with  his  individual  crop.  If  he  has  old 
trees,  he  should  know  the  variety  and  should  ascertain,  if  possible,  the 
probable  origin  of  this  variety  and  its  desirability  as  a  commercial 
product. 


CHAPTER  II 
THE  LIVING  PLANT 

PLANTS,  like  animals,  possess  the  power  to  grow  and  to 
reproduce.  Several  interesting  ways  of  reproduction  are  dis- 
cussed in  the  chapter  on  plant  propagation.  It  is  also  of 
value  to  the  horticulturist  to  know  something  of  the  structure 
of  plants  and  their  life  processes.  The  more  knowledge  he 
possesses  of  the  living  plant,  the  greater  is  his  power  to  make 
it  serve  his  purposes. 

25.  Parts  of  plants. — A  very  casual  observation  will  show 
that  the  roots,  stems,  leaves,  flowers,  and  fruits  are  the  main 
parts  of  our  common  plants.    The  plant  parts  are  made  up 
of  tissues  consisting  of  cells.    The  cell  is  the  unit  of  plant 
structure. 

26.  The  cell. — Robert  Hooke  in  1667,  while  examining 
the  bark  of  the  cork-oak  with  a  microscope,  noticed  very 
small  structures  which  looked  like  the  cells  of  honeycomb. 
He  called  these  plant-cells.    Although  most  plant-cells  are 
not  shaped  like  those  in  honeycomb,  the  name  given  by 
Hooke  is  still  applied  to  them,  no  matter  what  their  shapes 
may  be. 

27.  Number  of  cells  necessary  to  plant  life. — In  some 
cases,  single  cells  can  live  independently.    Such  a  cell  performs 
all  the  functions  necessary  to  life,  including  reproduction. 
The  so-called  " higher"  plants,  which  include  most  of  the 
cultivated  kinds,  are  made  up  of  a  number  of  cells,  and  are, 
therefore,  said  to  be  multicellular.    The  number  of  cells  in  a 
plant  may  be  very  large,  amounting  to  thousands  or  even 

16 


THE  LIVING  PLANT 


17 


millions.   They  are  of  various  sizes  and  shapes  (Fig.  2),  and  are 
modified  to  perform  definite  functions. 

28.  Structure  of 
plant-cells.— A  section 
of  a  living  cell  is  shown 
in  Fig.  3.  The  cell- 
wall  surrounds  a  mass 
within,  largely  made 
up  of  a  living  sub- 
stance called  proto- 
plasm. Protoplasm 
enters  into  the  com- 
position of  a  body 
within  the  cell  known  FlG"  2-~Plant-celIs  of  various  shaPes- 

as  the  nucleus.     The  part  of  the  protoplasm  between  the 
nucleus  and  the  cell-wall  is  known  as  cytoplasm.     In  the 


Cell  Wall- 


-Cell  Wai' 


-Ectoplasm 
-Nuc/eus 


FIG.  3. — A,  Diagram  of  a  cell.     B,  A  plasmolyzed  cell.    The  protoplasm  has  shrunk  to 
an  irregular  mass. 

cytoplasm  may  be  found  vacuoles,  granules,  plastids,  and 
crystals. 


18  HORTICULTURE  FOR  SCHOOLS 

29.  The  cell-wall  (Fig.  3)  is  non-living,  but  was  built 
up  by  the  living  part  of  the  cell.     It  varies  in  composition 
and  may  be  modified  in  a  number  of  ways  to  serve  different 
purposes.    The  cell-wall  acts  as  a  protective  covering  for  the 
living  protoplasm.     Solutions  usually  pass  readily  through 
the  cell-wall  inwardly  and  outwardly. 

30.  The  ectoplasm. — The  living  part  within  the  cell-wall 
is  surrounded  by  a  very  thin  membrane  called  the  ectoplasm, 
which  is  pressed  against  the  cell-wall  so  that  it  is  not  easily 
seen.    If,  however,  the  cell  is  placed  in  a  salt  solution,  some 
of  the  water  will  be  taken  out,  with  the  result  that  the  part 
within  will  shrink,  and  the  ectoplasm  will  become  separated 
from  the  cell- wall  (Fig.  3).    The  process  of  shrinkage  in  tvhis 
manner  is  called  plasmolysis.    The  ectoplasm  serves  to  give 
the  young  cell  support  before  the  cell-wall  is  formed,  and 
together  with  the  nucleus  controls  the  building  of  the  cell- 
wall  from  the  material  furnished  by  the  living  part  of  the  cell. 
The  ectoplasm  also  regulates  the  passage  of  solutions  into 
and  out  of  the  cell  by  its  power  of  selective  absorption;  that 
is,  it  allows  needed  materials  to  pass  into  the  cell,  but  keeps 
out  those  which  might  be  injurious  or  undesirable,  and  allows 
the  passage  of  some  materials  outward,  but  retains  others. 
In  this  way,  the  living  cell  is  allowed  to  select  the  materials  it 
needs. 

31.  Protoplasm. — Most  of  the  portion  within  the  cell- wall 
consists  of  a  complex  living  substance  called  protoplasm, 
which  is  necessary  to  all  forms  of  life.    As  has  been  seen, 
it  enters  into  the  composition  of  the  nucleus  and  cyto- 
plasm. 

32.  The  nucleus  may  be  spherical,  oval,  or  irregular  in 
shape.    It  may  be  in  the  center  of  the  cell  as  shown  in  the 
illustration  (Fig.  3)  or  at  the  side  near  the  cell-wall,  or  in  any 
other  part.    It  is  usually  found  near  the  portion  of  the  cell 
which  is  growing  most  actively.    The  nucleus  is  necessary  to 
the  life  of  the  cell  and  plays  a  very  important  part  in  its 


THE  LIVING  PLANT 


19 


-  Ce//  Wa// 


Nuc/eus 


Ce//Sap--     If-  — 


Sands  of 
Cytop/as/r, 


reproduction.  One  of  the  common  ways  in  which  it  aids 
reproduction  is  through  division,  whereby  two  cells  are 
developed  from  the  original  one. 

33.  Cytoplasm  (Fig.  3)  is  the  name  given   to   all  the 
protoplasm  within  the 

cell-wall,  with  the  ex- 
ception of  the  nucleus. 
Together  with  the  nu- 
cleus, it  carries  on  the 
activities  of  the  cell. 
It  contains  vacuoles, 
granules,  plastids,  and 
crystals. 

34.  Vacuoles. — In 
the  cytoplasm   occur 
what   frequently  ap- 
pear in  young  growing 
cells  to  be  small  glob- 
ules   of    clear  liquid. 
These  are  called  vac- 
uoles and  the  liquid 
is  known  as  cell-sap. 

As  the  cell  becomes  older,  the  vacuoles  become  larger  until 
frequently  a  single  vacuole  may  occupy  most  of  the  cell. 
In  the  cell-sap  are  acids  and  salts  which  cause  the  vacuoles 
to  take  up  and  hold  a  quantity  of  water,  enabling  the  proto- 
plasm to  fill  the  entire  cell  and  to  exert  pressure  against 
the  cell- wall.  This  pressure  is  called  turgor.  Turgor  is 
necessary  for  the  enlargement  of  the  growing  cell  and  gives 
strength  to  the  plant.  When  turgor  is  wanting,  as  in 
herbaceous  plants  which  have  wilted,  the  soft  tissues 
collapse  and  the  plant  loses  its  rigidity.  The  vacuoles 
store  manufactured  food  materials  until  they  are  needed 
by  the  cell.  They  contain  also  excretory  products  which  the 
protoplasm  cannot  use. 


FIG.  4. — Cell  showing  circulation  of  the  cytoplasm 
(streaming).  Arrows  show  direction  of  move- 
ments. 


20  HORTICULTURE  FOR  SCHOOLS 

35.  Plastids  are  small  bodies  contained  within  the  cyto- 
plasm. They  possess  the  power  of  growth  and  multiplication 
by  division.  There  are  three  types.  The  leucoplasts  are 
colorless.  Their  function  is  to  change  soluble  sugars  into 

insoluble  starch  grains  which 
they  store  within  themselves. 
The  chloroplasts  are  green  in 
color  and  are  necessary  in 
the  manufacture  (photosyn- 
thesis)  of  plant-food.  The 
chromoplasts  are  red,  yellow, 
or  o^nge  in  color  and  some- 
times  crystalline  in  form  (Fig. 
5)  .  The  colors  of  many  flowers 

tO 


F.o.S.-Chroroopastsofvariousshapes: 

presence. 

36.  Functions  of  plant  parts.  —  As  has  been  stated,  the 
parts  of  the  plant  consist  of  a  large  number  of  cells,  many  of 
which  are  highly  specialized  to  perform  certain  definite  kinds 
of  work,  but  all  of  which  work  together  for  the  good  of  the 
plant.  Each  part  of  the  plant  performs  certain  functions. 
For  the  convenience  of  the  student,  the  uses  of  the  roots, 
stems,  leaves,  flowers,  and  fruits  are  summarized  in  the 
following  : 

FUNCTIONS  OF  PLANT  PARTS 


I.     The  Roots    .   . 


II.     The  Stem  . 


1.  Absorb  water  and  food  materials. 

2.  Transport  water  and  food  materials. 

3.  Store  food  material. 

4.  Fix  the  plant  in  a  definite  place  and 

position. 

1.  Transports  water  and  food  materials. 

2.  Holds  the  leaves  up  into  the  sunshine 

and  air. 

3.  Stores  food  material  in  many  cases. 


THE  LIVING  PLANT 


21 


III.     The  Leaves  . 


IV.     Flowers  and  Fruits 


1.  Manufacture  food  material  for  use  in 

the  plant. 

2.  Respire. 

3.  Transpire. 

4.  Shade  the  stem. 

1.     Form  seeds  in  order  to  produce  new 
plants. 


37.  Roots  (Figs.  6  and  7).  —  As  to  shape,  roots  may  be 
placed  in  three  classes:  (1)  Tap-roots  are  thick  and  tapering. 
Such  roots  may  be  several  inches  in  length,  as  in  the  carrot 

and  the  beet,  or  may  be  a  number  of  feet  long,  as 

in  the  walnut  and  pecan.    (2)  Fascicled  roots  are 

thick  and  fleshy, 

but  somewhat  ir- 

regular in  shape, 

as  in  the  sweet 

potato.    (3)    Fi- 

brous roots   are 

long,  slender, 

and  more  or  less 

crooked.       Such 

roots  spring  from 

tap-roots   and 

fascicled  roots, 

or  are  found  on 

plants  having  neither  tap-  nor  fascicled  roots. 
38.  Manner  of  growth  of  roots.  —  As  the  plant 

growg)  ^ne  roots  increase  in  length  by  the  mul- 
tiplication and  enlargement  of  cells  near  the  tip.  As  a  root 
pushes  through  the  soil,  it  is  protected  by  a  root-cap  consist- 
ing of  a  number  of  modified  cells  (Fig.  8).  Branch  roots  arise 
from  older  roots  in  a  different  manner  than  do  the  branches  of 
stems.  The  branch  (lateral)  roots  grow  out  from  the  central 
interior  portion  of  older  roots,  while  the  lateral  branches  of 
stems  arise  from  buds  formed  by  the  outer  tissue  of  the  stem. 


FIG.  7. — Fascicled  roots  of  the  sweet  potato. 


FIG.  6.—  Tap- 
jarrot. 


22 


HORTICULTURE  FOR  SCHOOLS 


FIG.  9. — Root/- 
hairs  on  young 
radish. 


39.  Functions  of  roots. — Plants  depend  on  the  roots  for 
the  absorption  from  the  soil  of  water  and  substances  in  solu- 
tion to  be  manufactured  by 
certain  cells  into  food  material. 
The  main  part  of 
the  root  does  not 
absorb  such  ma- 
terial, but  the 
absorption  is  by 
specialized  cells 
known  as  root- 
hairs  (Fig.  9).  A 
root-hair  is  a 
single,  elongated, 

*****  Csf> -m^mm^/  living  cell,  consist- 

ing of  the  usual 
parts  of  the  cell 
(Fig.  10).  Root-hairs  are  pro- 
duced by  the  outside  (epider- 
mal) tissue  of  the  root,  and  occur  near  the  growing  point  of  the 
root.  If  plants  are  dug  up  carefully  and  the  soil  washed  from 
the  small  fibrous  roots,  the  root-hairs  can  be  seen  readily.  The 
root-hairs  are  short-lived  and  are  found  only  on  the  young  roots 
near  the  tips.  As  the  roots  get  older,  the  root-hairs  farthest 
back  gradually  die  and  are  replaced  by  those  growing  near 
the  tip. 

The  root-hairs  absorb  solutions  from  the  soil  by  osmosis. 
The  process  of  osmosis  can  easily  be  illustrated  artificially  by 
an  old  experiment.  A  thistle-tube  is  filled  with  molasses  or 
sugar  solution,  and  a  membrane  such  as  a  pig's  bladder  or 
parchment  paper  is  tied  across  the  large  end.  The  tube  is 
then  inserted  in  a  beaker  of  water  with  the  large  end  down  so 
that  the  membrane  is  submerged  in  water.  A  rise  of  liquid 
in  the  tube  shows  that  the  dilute  solution  is  passing  through 
the  membrane  into  the  denser  sugar  or  molasses  solution. 


FIG.  8. — Tip  of  root  showing  root-cap. 


THE  LIVING  PLANT 


23 


The  dense  solution  also  passes  through  the  membrane  into 
the  weaker  solution  as  can  be  noticed  by  the  sweet  taste  of 
the  water  in  the  beaker,  but  most  of  the  passage  is  from  the 

weaker  to  the  stronger  concentrated  _____ __ 

solution.  The  passage  of  solutions 
of  different  densities  through  semi- 
permeable  membranes  into  other 
solutions  in  this  way  is  known  as 
osmosis.  The  root-hairs  are  able  to 
take  up  water  and  substances  in 
solution  because  the  cell-sap  is  of  Ceff  Wa//—» — 
greater  concentration  than  the  solu- 
tions in  the  soil.  But  if  the  solu- 
tions in  the  soil  should  become 
stronger  than  the  cell-sap  in  the 
root-hairs,  the  cell-sap  would  move 
outward  into  the  soil  solutions,  and 
injury  or  death  to  the  plant  would 
be  the  final  result.  This  is  one 
reason  why  plants  cannot  grow  in 
soils  strongly  alkaline. 

Before  the  salts  taken  up  by  root-hairs  can  be  used  by  the 
plant,  they  must  be  transported  through  the  roots  and  stem 
to  the  leaves  where  they  are  manufactured  into  plant-foods. 
It  is  important  to  understand  that  the  older  roots  do  not 
absorb  solutions,  but  carry  them. 

Roots  also  serve  as  storehouses  for  food  materials,  most  of 
which  are  in  the  form  of  starches-.  Thick  fleshy  roots  possess 
a  large  amount  of  stored  food.  Plants  living  two  years 
(biennials)  usually  do  not  produce  seed  the  first  year,  but 
manufacture  and  store  up  food  in  the  roots.  The  stored  food 
is  used  the  second  year  to  aid  in  producing  the  top  of  the  plant, 
and  the  thick  roots  shrivel.  The  plant  produces  seed  the 
second  year  and  then  dies,  root  and  top.  Carrots,  parsnips, 
and  the  like,  are  examples. 


Nucleus 


FIG.  10 — Root-hair  magnified. 


24  HORTICULTURE  FOR  SCHOOLS 

40.  The  stem. — Many  kinds  of  stems  are  common  to 
plants.    Some  are  herbaceous  and  consist  almost  entirely  of 
living  tissue;   others  are  woody  and  consist  largely  of  dead 
tissue.    Stems  may  be  long  or  short,  slender  or  thick.    They 
may  run  along  the  ground  as  in  many  vines,  or  may  climb 
or  twine  around  supports,  or  may  be  of  such  strength  as 
to  hold  their  foliage   up  into  the   air  and   light   without 
assistance. 

41.  Structure  and  functions  of  the  stem. — In  the  young 
stem,  or  very  young  growing  portions  of  older  stems,  the  cells 


I   Vascu/ar 
{Bund/e 


Pith 


FIG.  11. — A,  Cross-section  of  very  young  growing  portion  of  exogenous  stem  with  cells 
nearly  alike.     B,  An  older  stem  with  various  tissues  developing. 

are  much  alike.  Later  they  become  differentiated.  Figs.  11 
and  12  show  the  appearance  in  cross-section  of  a  number  of 
bundles  (vascular  bundles)  in  the  pith  of  a  stem.  The  inner 
side  of  each  bundle  consists  of  various  modified  cells  which 
later  form  the  woody  portion  of  the  plant  known  as  the  xylem. 


THE  LIVING  PLANT 


25 


The  outer  portion  of  each  bundle  also  consists  of  modified 

cells  and  is  known  as  the  phloem,  or  true  bark.    Between  the 

phloem  and  the  xylem  is  a  thin  tissue  of  cells  known  as 

the  cambium.    It  will 

also  be  seen  that  the 

cambium   extends    in 

a  circle   through  the 

pith.     The    cambium 

cells  are  the  growing 

portions  and  build  up 

the  other  parts  of  the 

stem.     It  is  through 

the  vascular   bundles 

that   solutions   travel 

upward    and     down-  V&8&W-™  o«r* 

ward  through  the 

tree.     The    solutions 

travel  upward  almost 

entirely  through    the 

xylem  and  downward 

through  the  phloem.    Specially  modified  cells,  called  tracheal 

tubes,  occur  in  the  xylem  for  the  passage  of  solutions  upward. 

Other  modified  cells,  known  as  sieve-tubes,  are  present  in 

the  phloem  for  the  passage  of  the  solutions  downward. 

Both  of  these  types  of  cells  carry  solutions  after  the  cells  are 

dead.    They  are  illustrated  in  Fig.  12.    These  are  not  the 

only  types  of  cells  in  the  vascular  bundles.     It  should  be 

noticed  also  that,  although  most  of  the  movement  of  solutions 

through  the  stem  is  upward  and  downward,  some  movement 

takes  place  in  other  directions. 

As  the  stem  becomes  older,  the  vascular  bundles  press  the 
pith  between  them  into  thin  plates  called  medullary  rays. 
In  old  stems  the  xylem  forms  a  continuous  ring  of  wood  and 
the  phloem  a  continuous  ring  of  bark  with  the  cambium 
between  the  wood  and  bark.  Each  growing  season  the  cam- 


FIG.  12. — A  section  of  same  stem  as  in  Fig.  11,  older, 
with  vascular  bundles  closer  together  and  pith 
between  compressed  into  medullary  rays. 


26 


HORTICULTURE  FOR  SCHOOLS 


FIG.  13. — Cross-section  of  exogenous  stem  show- 
ing annular  rings  of  wood. 


bium  forms  a  layer  of  bark  inside  the  old  bark.  As  a  ring  of 
wood  is  added  every  growing  season,  the  age  of  a  section  of 
a  stem  can  be  told  approximately  by  counting  the  rings. 
Because  the  stem  is  increased  in  diameter  by  layers  of  wood 

on  the  outside,  this  type 
of  stem  is  said  to  be 
exogenous  (Fig.  13).  Most 
trees  are  exogens.  It  is 
important  to  remember 
that  in  exogenous  stems, 
the  solutions  pass  upward 
through  the  wood  or 
xylem  inside  the  cam- 
bium layer,  while  most 
of  the  passage  downward 
is  in  the  bark  or  phloem 
just  outside  of  the  cam- 
bium layer. 

Another  type  of  stem  is  that  in  which  the  vascular  bundles 
are  not  arranged  in  circles  but  are  scattered  throughout  the 
stem  (Fig.  14).  Each  vascular  bundle  is  similar  in  structure  to 

those  already  mentioned  and  the 
solutions  pass  through  them  in  the 
same  way,  but  rings  of  wood  are 
never  formed.  Because  the  growth 
takes  place  on  the  inside,such  plants 
are  called  endogens,  and  include 
palms,  corn,  and  all  true  grasses. 

Stems  store  food  materials  for 
future  use,  usually  in  the  forms  of 
starches,  which  are  insoluble.  It 

FIG.  14.— Cross-section    of  endoge-    Ql^,,!  J     UA    vommYiKprAr}    that   fnnrl 
nous  stem  showing  scattered  ar-    SnOUld     I 
rangement  of  vascular  bundles.      materials  can  be  transported  by  the 

plant  only  in  soluble  forms,  such  as  sugars,  but  that  they  are 
changed  into  starches  in  order  to  be  insoluble  for  storage. 


THE  LIVING  PLANT  27 

Before  stored  food  can  be  used  by  the  plant,  it  must  be 
changed  again  into  soluble  forms.  By  action  of  certain 
substances  known  as  enzymes  or  ferments,  plants  are  able 
to  change  starches  to  sugars  and  sugars  to  starches  readily. 

42.  Growth  of  stems. — How  stems  grow  in  diameter  has 
already  been  explained.    Stems  elongate  from  growing  points 
or  buds.    An  examination  will  show  that  there  are  nodes  or 
joints  at  the  points  from  which  the  leaves  grow  out.   The  parts 
between  the  nodes  are  designated  internodes.     The  inter- 
nodes  do  not  elongate  after  the  first  growing  season  is  past. 

43.  Buds. — Several  kinds  of  buds  are  formed  from  certain 
tissues  of  the  outer  portion  of  stems.    Buds  may  be  classified 
according  to  function  as  leaf,  flower,  and  mixed  buds.     A 
leaf -bud  consists  of  a  very  short  axis  having  internodes  so 
short  that  the  nodes  are  packed  closely  together.    At  these 
nodes  are  very  small  undeveloped  leaves.    The  bud  may  be 
covered  with  protective  scales,  as  in  most  perennials  (plants 
which  live  for  more  than  two  years),  or  they  may  not  have 
protective  scales  and  are  then  said  to  be  naked,  as  in  many 
herbaceous  plants.    A  leaf-bud  is  really  a  potential  stem.    It 
elongates  into  a  stem  and  its  leaves  develop  into  the  foliage. 
A  flower-bud  develops  into  flowers  which  under  favorable 
conditions  set  fruit.     The  number  of  flowers  differs  in  the 
various  buds;  for  example,  in  the  cherry  the  number  is  from 
three  to  five,  in  the  plum  two  or  three  are  common.    Mixed 
buds  contain  both  flowers  and  leaves,  as  in  the  apple. 

Buds  may  be  active,  dormant,  or  adventitious.  Active 
buds  are  those  that  grow  under  normal  conditions.  Dormant 
buds  do  not  grow  to  any  extent,  but  possess  the  power  of 
growth  should  favorable  conditions  arise.  As  a  rule,  buds  near 
the  tip  of  twigs  are  more  active  than  those  at  the  base,  many 
of  which  are  dormant  during  the  growing  season.  Of  course, 
all  buds  are  dormant  in  the  winter  in  cold  climates.  Adventi- 
tious buds  are  not  visible  but  arise  from  unusual  conditions, 
such  as  injury. 


28 


HORTICULTURE  FOR  SCHOOLS 


A- 


-B 


As  to  position,  buds  may  be  terminal,  on  the  tip  of  the 
stem;  or  lateral,  on  the  side  of  the  stem  (Fig.  15).    Lateral 
buds  always  originate  in  the  axils  of  leaves, 
that  is,  in  the  angle  where  the  leaf  joins  the 
stem.     The  leaves  fall,  finally, 
leaving  scars,  above  which  the 
buds  can  be  seen.     The  or- 
dinary  active   bud  continues 
the  growth  the  year  following 
the  dropping    of   the  leaf  in 
whose  axil  it  was  borne. 

44.  Fruit  -  buds.  —  Flower- 
or  fruit-buds  are  formed  from 
the  same  kind  of  tissue  as  are 
leaf -buds.  Very  early  in  their 
development  it  is  difficult  to 
tell  which  are  flower-  and 
which  leaf-buds,  even  when 
microscopic  sections  are  made.  FlQ 
Later  the  differentiation  is  so 
marked  that  fruit-buds  can  be 
easily  distinguished  from  leaf- 
buds  with  the  microscope. 
When  well  developed,  the 
flower-buds  can  usually  be  identified  by  their 
plump  appearance  and  by  the  fact  that  they  stand  out 
from  the  stem  more  than  the  leaf-buds  and  are  not  so  sharp 
and  pointed.  In  many  cases,  they  may  be  distinguished  from 
the  leaf -buds  by  their  arrangement  or  position  on  the  stem. 
For  example,  many  of  the  stone-fruits  bear  fruit-buds  on  the 
lateral  (side)  branches,  where  the  buds  occur  at  the  nodes  in 
threes,  the  middle  one  being  a  leaf-bud  and  the  outer  two 
fruit-buds  (Fig.  16).  The  peach  tree  bears  its  fruit  in  this 
manner  on  wood  formed  in  the  previous  season.  This  must 
be  taken  into  account  when  pruning.  It  is  necessary  not 


AndteSlibu<B 

lateral.  ' 


16. — Peach 
twi  g  showing 
habit  of  bearing. 
The  buds  are 
borne  at  the  nodes 
in  threes,  the 
middle  one  being 
a  leaf-bud  and 
producing  a  stem 
bearing  leaves; 
the  two  outer  are 
fruit-buds. 


THE  LIVING  PLANT  29 

only  to  thin  out  branches  to  admit  light,  but  also  to  leave 
a  proper  amount  of  the  lateral  growth  so  distributed  as  to 
bear  the  crop  in  the  best  way. 

Fruit-buds  are  sometimes  borne  on  spurs.  A  spur  is  merely 
a  very  short  condensed  branch.  Spurs  may  live  to  bear  one 
crop  only  as  in  the  almond,  or  may  live  for  a  few  years  as  in 
the  apricot,  or  may  live  for  a  long  time  as  in  the  apple.  In 
trees  which  bear  fruit  on  spurs,  it  is  very  important  in 
pruning  to  preserve  the  spurs.  This  is  especially  true  of  the 
apple  and  pear. 

The  following  shows  the  way  in  which  fruit-buds  are  borne 
on  several  kinds  of  trees: 

SPECIES  OF  TREES  How  FRUIT-BUDS  ARE  BORNE 

Peach On  laterals 

European  plums      Mostly  on  spurs 

Japanese  plums On  spurs  and  on  laterals 

Almond Mostly  on  spurs 

Cherry      On  spurs 

Apricot On  spurs  and  on  laterals 

Apple On  spurs  entirely,  except  in  some  of 

the  western  states  where  the  ter- 
minal buds  also  frequently   bear 
fruit 
Pear      Same  as  for  the  apple 

An  apple  spur  does  not  bear  fruits  annually  but  only  every 
other  year  (Fig.  17).  If  it  bears  a  fruit  on  its  terminal  bud 
in  1922,  it  forms  a  leaf-bud  on  the  side  which  continues  the 
growth  of  the  spur  in  1923.  In  1923  a  fruit-bud  is  formed  on 
the  end  of  the  spur  which  bears  a  fruit  in  1924.  Usually  some 
of  the  spurs  bear  fruit  one  year  and  others  the  next,  so  that  a 
crop  is  obtained  every  year,  but  many  times  all  the  spurs 
bear  fruit  the  same  year  and  not  the  next,  in  which  case  a 
crop  is  obtained  every  other  year  only.  Some  trees  are  more 
likely  to  have  this  habit  of  alternate  bearing  than  others,  but 
frequently  unusual  conditions  are  responsible  for  it.  It  is 
difficult  to  get  trees  out  of  the  habit  when  once  it  is  estab- 


30 


HORTICULTURE  FOR  SCHOOLS 


lished.  It  is  possible  that  at  some  future  time  methods  of 
pruning,  culture,  and  irrigation  may  be  devised  which  will 
overcome  alternate  bearing  in  fruit-trees. 

45.  The  leaves. — Leaves  generally  have  two  parts,  the 
blade  and  the  stalk  (petiole).  Sometimes  smaller  leaf -like 
structures,  called  stipules,  are  borne  at  the  base  of  the 
petiole,  as  in  the  leaves  of  many  varieties  of  apples.  When 
leaves  have  no  petioles,  they  are  said  to  be  sessile.  When 


apples  have 
been  borne  by  the  spur 
and  this  year's  apple  is 
still  on  the  twig. 


the  blade  of  a  leaf  is  single,  it  is  simple  as  in  the  plum  or 
cherry,  and  when  the  blade  is  divided  into  a  number  of  small 
leaves,  as  in  the  carrot,  it  is  compound.  Leaves  may  be 
parallel-veined  as  in  the  grasses,  or  netted-veined  as  in  the 
apple  or  peach.  Netted-veined  leaves  grow  on  exogenous 
stems,  and  parallel-veined  leaves  on  endogenous  stems. 
Leaves  vary  greatly  in  size,  shape,  thickness,  and  markings. 

46.  Structure  of  leaves. — Vascular  bundles  run  up  from 
the  stem  through  the  petiole  and  into  the  tissues  of  the  blade 
of  the  leaf,  subdividing  and  becoming  smaller  until  they  end 
in  a  few  rows  of  cells.  The  vascular  bundles  carry  water  and 
food  material  in  solution  to  and  fro,  and  also  strengthen  the 
leaves. 

The  structure  of  a  leaf  is  best  shown  by  a  cross-section  dia- 
gram. The  upper  and  lower  surfaces  of  the  leaves  are  covered 


THE  LIVING  PLANT 


31 


FIG.  18. — Portion  of  a  cross-section  of  a  leaf  showing 
different  cells. 


by  a  single  layer  of  cells  known  as  the  epidermis  (Fig.  18). 
In  the  epidermis  are  small  openings  called  the  stomata.1 
Each  stoma  lies  between  two  modified  cells,  called  guard-cells. 
These  open  and 
close,  thus  regu- 
lating the  size  of 
the  stoma.  Un- 
derneath the 
upper  epidermis 
are  one  or  more 
layers  of  cells, 
which,  because 
of  their  long 
shape ,  are 
termed  palisade- 
cells.  These  con-  *«$3fcww 
tain  chloroplasts 
and  chlorophyll, 
a  green  colored  substance.  Beneath  the  palisade-cells  are 
irregular-shaped  thin-walled  cells  (parenchyma  cells)  and 
between  them  are  air  spaces  (intercellular  spaces). 

47.  The  functions  of  leaves  (Fig.  19). — Leaves  are  very 
important  plant  organs.  One  function  is  that  of  transpira- 
tion, or  the  "  giving  off  "  of  water  in  the  form  of  vapor.  Leaves 
give  off  moisture  for  two  reasons.  In  the  first  place,  transpi- 
ration regulates  the  temperature  of  the  plant.  Secondly,  the 
plant  takes  up  more  water  than  it  can  use  in  order  to  obtain 
the  necessary  amount  of  soluble  food  materials.  It  must  get 
rid  of  the  surplus  water,  which  it  does  through  the  little  open- 
ings (stomata)  in  the  epidermis  of  the  leaves.  The  guard- 
cells  resemble  in  shape  the  halves  of  a  doughnut.  When 
there  is  plenty  of  moisture,  the  guard-cells  are  full  of  water 
and  are  turgid  so  that  between  them  there  is  a  wide  opening. 
If  for  any  reason  moisture  is  lacking  in  the  plant,  transpiration 

1  Singular — stoma. 


32 


HORTICULTURE  FOR  SCHOOLS 


lessened 
smaller 


by  the  guard-cells  shrinking  together  and  leaving 
opening.     The  quantity  of  water  transpired  by 

plants  is  very  great, 
in  many  species  be- 
ing equivalent  in  a 
season  to  several 
hundred  times  the 
weight  of  dry  mat- 
ter in  the  plant. 

The  second  func- 
tion of  leaves  is  res- 
piration, in  which 
the  leaves  take  in  and 
give  off  the  same  kind 
of  gases  as  do  human 
beings  when  they 
breathe.  Leaves  re- 
spire more  or  less  all 
the  time,  both  day 
and  night.  In  respi- 
ration, oxygen  is 
taken  in  from  the  air 
and  carbon  dioxide  is 
given  off.  The  pur- 
pose of  respiration  is 
to  supply  energy. 

The  most  impor- 
tant function  of  the 
leaves  is  photosyn- 
thesis, or  the  manu- 
facturing of  food 
material  by  the  aid  of 
light.  As  light  is 
necessary  for  photo- 
synthesis, the  plants 


THE  LIVING  PLANT  33 

manufacture  food  materials  in  the  daytime  only.  Briefly  the 
process  is  as  follows :  Water  is  taken  up  by  the  root-hairs  and 
transported  to  the  leaves.  Carbon  dioxide  in  the  air  is  taken 
in  by  the  leaves  through  the  stomata.  The  water  and 
carbon  dioxide  are  broken  up  and  united  in  the  leaves  to 
form  sugars,  and  oxygen,  a  waste  product  of  the  process, 
is  given  off.  The  process  takes  place  extensively  in  the 
palisade-cells  of  the  leaves  through  the  action  of  chlorophyll, 
a  greenish-colored  oily  liquid,  for  the  production  of  which 
light  is  necessary.  It  is  well  known  that  plants  grown  in  the 
dark  lack  chlorophyll.  This  explains  their  pale  coloring. 
It  will  be  seen  that  light  supplies  the  energy  for  photo- 
synthesis, that  chlorophyll  does  the  work,  and  that  carbon 
dioxide  and  water  are  the  materials  from  which  the  sugars 
are  made.  The  process  is  complicated  as  there  are  several 
chemical  steps  before  sugar  is  manufactured.1  The  amount 
of  sugar  manufactured  is  considerable  but  varies  with  different 
plants.  Other  forms  of  sugar,  as  well  as  grape  sugar,  are 
found  in  the  plant.  Protein  materials  also  are  manufactured 
by  plants,  and  certain  fats  and  oils.  The  manufactured 
carbohydrate  food  material  is  transported  to  the  different 
parts  of  the  plant  in  the  form  of  sugars,  which  are  soluble,  and 
is  stored  in  the  form  of  starches,  which  are  insoluble. 

It  will  be  seen  that  the  chemical  process  in  photosynthesis 
is  the  opposite  of  that  in  respiration,  and  also  that  the 
materials  used  and  waste  products  in  photosynthesis  are 
different  than  in  respiration.  It  should  be  remembered  that 
in  respiration,  oxygen  (0)  is  used,  and  carbon  dioxide  (CO2) 
is  given  off  day  and  night,  while  in  photosynthesis,  carbon 
dioxide  (C02)  is  used  and  oxygen  (O)  is  given  off  in  the  day- 
time only.  During  the  night,  when  respiration  only  is  taking 
place,  a  small  quantity  of  carbon  dioxide  (CO2)  is  given  off 

JThe  chemical  reaction  may  be  summed  up,  however,  as  follows:  Carbon 
dioxide  6CO2  plus  water  (6H2O)  form  grape  sugar  (CsHuOe) ,  and  oxygen 
(6O2)  is  a  waste  product. 


34  HORTICULTURE  FOR  SCHOOLS 

by  the  plants,  but  in  the  daytime,  when  both  respiration  and 
photosynthesis  are  taking  place,  all  the  carbon  dioxide 
liberated  by  respiration  is  used  in  photosynthesis  and  does 
not  get  back  into  the  air.  In  addition,  a  large  quantity 
of  carbon  dioxide  is  taken  out  of  the  atmosphere  and  a 
considerable  quantity  of  oxygen  is  added  to  the  air.  On  the 
whole,  then,  plants  take  carbon  dioxide  from  the  air  and  add 
oxygen  to  it. 

It  is  of  interest  to  note  that  the  plant  obtains  hydrogen 
from  the  water  in  the  soil  taken  up  by  the  roots;  that  oxygen 
is  secured  from  this  source  and  from  the  air  taken  in  by  the 
leaves;  that  carbon  is  taken  in  by  the  leaves  from  the  air; 
that  nitrogen  must  be  secured  from  the  soil  in  the  form  of 
salts  by  all  plants  except  the  legumes  which,  by  means  of  the 
bacteria  living  in  nodules  on  the  roots,  are  able  to  use  the 
nitrogen  of  the  air;  and  that  phosphorus,  potassium, 
magnesium,  sodium,  calcium,  iron,  chlorin,  and  sulfur  must 
be  taken  from  the  soil  in  the  form  of  salt  compounds. 


EXERCISES 

EXERCISE  I. — Exercises  in  plant  structure. 

1.  Materials. — Various  plants  with  their  roots. 

Procedure. — Classify  the  plants  according  to  their  root  systems  into 
those  possessing  the  following:  (a)  fibrous  roots,  (b)  tap-roots,  (c) 
fascicled  roots.  Arrange  your  results  in  the  form  of  a  table. 

2.  Materials. — Plants;  shrubs;  small  trees  with  their  roots. 
Procedure. — Dig  up  carefully  various  plants  and  if  possible  small 

trees.  Examine  them  for  root-hairs.  Notice  especially  their  number 
and  where  they  are  borne. 

3.  Materials. — Exogenous  and  endogenous  stems;  microscope. 
Procedure. — (a)  Examine  longitudinal  and  cross-sections  of  exogenous 

stems.  Study  their  general  structure.  Draw  and  label  the  parts. 
Make  thin  sections  of  young  stems  and  examine  them  under  a  micro- 
scope for  cells  of  various  shapes,  (b)  Examine  longitudinal  and  cross- 
sections  of  endogenous  stems. 

4.  Materials. — Leaves:  microscope. 


THE  LIVING  PLANT  35 

Procedure. — Place  a  piece  of  thin  leaf  under  a  microscope.  Examine. 
In  some  leaves  the  cells  can  be  seen  distinctly,  and  in  most  leaves  the 
green  chlorophyll  granules  can  be  seen. 

5.  Materials. — Geranium  or  other  leaves;   microscope,  glass  slides. 
Procedure. — Strip  off  a  portion  of  the  epidermis  of  a  leaf,  mount  it 

in  water  on  a  slide  and  examine  it  under  a  microscope  for  a  view  of  the 
stomata.  Notice  the  guard-cells.  Make  an  enlarged  drawing  of  the 
surface  view  of  a  stoma.  Where  do  you  find  the  most  stomata,  on  the 
upper  or  lower  surface  of  the  leaves  examined?  Account  for  this  fact. 

6.  Materials. — Various  kinds  of  plants  and  trees. 

Procedure. — Examine  the  leaves  of  a  number  of  plants  and  trees. 
Classify  them  into  the  following:  (a)  simple  and  compound  leaves; 
(b)  netted- veined  and  parallel- veined  leaves;  (c)  leaves  with  and 
without  stipules;  (d)  which  of  the  plants  in  the  list  examined  would 
you  expect  to  have  endogenous  stems  and  which  exogenous? 

7.  Materials. — Trees  of  the  apple,  pear,  apricot,  plum,  or  others 
having  fruit-spurs. 

Procedure. — Study  and  draw  different  types  of  fruit-spurs.  Compare 
the  length  of  internodes  on  a  spur  with  that  on  an  ordinary  branch. 
Are  the  leaves  and  buds  arranged  in  the  same  way  on  a  spur  as  on  an 
ordinary  branch?  In  what  respects  does  a  spur  differ  from  an  ordinary 
branch  and  in  what  respects  is  it  similar? 

8.  Materials. — Various  trees. 

Procedure. — Study  leaf-buds.  Starting  at  the  base  of  a  bud,  remove 
the  bud-scales  in  order.  Compare  the  arrangement  of  the  scales  on  a 
bud  with  that  of  the  leaves  on  a  stem,  and  also  compare  the  number 
of  leaves  on  a  stem  with  the  number  of  scales  on  a  bud.  How  does  a 
bud  differ  from  a  stem? 

9.  Materials. — Trees  just  before  or  just  at  blossoming  and  leafing- 
out  time  in  the  spring. 

Procedure. — Examine  trees  of  various  kinds  for  leaf-buds,  flower-buds, 
and  mixed  buds.  Keep  a  list  of  the  types  of  buds  found  on  the  various 
trees. 


EXERCISE  II. — Exercises  to  determine  the  growing  portions  of  plant 
parts. 

1.  Materials. — Water-proof  ink;  ruler;  young  growing  pea,  corn, 
or  other  plants. 

Procedure. — With  water-proof  ink  place  marks  one  millimeter  apart 
along  a  small  rootlet,  along  the  growing  stem,  and  along  the  main  rib 
of  a  leaf.  In  like  manner  mark  the  entire  surface  of  a  leaf  in  squares. 


36  HORTICULTURE  FOR  SCHOOLS 

Examine  the  marked  parts  from  time  -to  time  to  see  where  the  marks 
are  farthest  apart.  Which  are  the  most  rapidly  growing  portions  in 
each  case? 

2.     Materials, — Trees  with  growing  shoots;  labels. 

Procedure. — (a)  As  early  in  the  growing  season  as  possible,  select 
and  label  a  growing  shoot  on  any  convenient  tree.  Make  a  drawing 
of  the  shoot  showing  nodes  and  internodes.  Measure  the  length  of  the 
internodes  and  record  the  results  on  your  drawing.  Repeat  the  measure- 
ments every  two  weeks.  Report  the  results,  (b)  Proceed  in  the  same 
way  with  a  branch  two  years  or  more  of  age  on  the  same  tree.  Do  the 
internodes  lengthen?  (c)  What  bearing  have  the  facts  learned  in  this 
exercise  on  pruning  and  forcing  the  height  of  head  of  a  young  tree? 

EXERCISE  III. — Exercise  to  show  the  presence  of  water  in  plant 
tissues. 

Materials. — Cans  or  evaporating  dishes;  small  scales;  leaves;  twigs 
from  a  tree;  oven. 

Procedure. — (a)  Weigh  out  some  fresh  leaves  in  cans  or  evaporating 
dishes.  Record  the  weights.  Dry  the  leaves  in  an  oven  for  a  number 
of  hours,  at  a  temperature  of  about  212  degrees  F.  Then  weigh  the  leaves 
again.  The  difference  in  weight  is  due  to  the  loss  of  water.  Compute 
the  percentage  of  water  contained  in  the  leaves.  Compare  your  results 
with  those  of  others  in  the  class,  (b)  Repeat  the  experiment  with  young 
twigs  cut  into  small  pieces.  Obtain  the  percentage  of  water. 

EXERCISE  IV. — Exercise  to  illustrate  osmosis  or  the  way  in  which 
root-hairs  absorb  moisture. 

Materials. — Thistle-tube;  stand  and  clamp  for  holding  thistle- tube ; 
parchment  paper  or  pig's  bladder;  molasses  or  sugar  solution;  beaker 
of  water. 

Procedure. — Perform  the  experiment  described  in  paragraph  39. 

EXERCISE  V. — Exercise  to  show  that  the  epidermis  prevents  unneces- 
sary evaporation  of  moisture. 

Materials. — Geranium  stems. 

Procedure. — Divide  the  stems  into  two  portions.  After  removing 
the  leaves,  peel  the  outer  tissue  (bark)  from  one  portion.  Weigh  each 
portion  separately.  Place  both  portions  in  the  sun  and  after  a  time 
weigh  again.  Note  the  difference  in  loss  of  moisture.  (The  same 
experiment  may  be  done  with  fruits  of  the  apple,  pear,  or  orange.) 


THE  LIVING  PLANT  37 

EXERCISE  VI. — Exercises  in  plasmolysis  and  turgidity. 

1.  Explain  and  illustrate  with  drawings  plasmolysis  of  a  cell. 

2.  Materials. — Stems  of  various  plants  such  as  geranium,  alfalfa, 
marguerite,  grape,  cactus,  peach  twig,  olive  or  oleander  twig,  pine 
twig. 

Procedure. — Allow  the  stems  to  wilt  for  various  lengths  of  time  and 
then  place  them  in  water.  What  is  the  cause  of  the  wilting?  To 
what  extent  is  it  possible  to  let  the  stems  wilt  and  have  them  recover? 
Does  wilting  injure  all  plants  to  the  same  extent?  What  effect  has 
wilting  on  cuttings  or  young  trees  to  be  planted? 

EXERCISE  VII. — Experiment  illustrating  the  ascent  of  water  in 
plants. 

Materials. — Fresh  growing  stems  of  willow  or  orange;   eosin  solution. 

Procedure. — Place  the  stem  in  dilute  eosin  solution  with  the  cut  end 
downward.  After  a  time  trace  the  upward  path  of  the  water  by  the 
red  color.  What  part  of  the  stem  carries  the  water  upward?  What 
effect  would  the  girdling  of  the  bark  of  a  tree  have  on  the  upward 
passage  of  water? 

EXERCISE  VIII. — Experiment  to  illustrate  transpiration 

Materials. — Two  tumblers;    cardboard;    geranium  or  other  leaf. 

Procedure. — Nearly  fill  a  tumbler  with  water.  Punch  a  hole  in  the 
center  of  a  piece  of  cardboard  and  put  the  petiole  of  a  leaf  through  the 
hole.  Place  the  cardboard  on  top  of  the  tumbler  so  that  one  end  of 
the  petiole  projects  into  the  water.  Place  a  dry  tumbler  inverted  upon 
the  cardboard  so  as  to  cover  the  blade  of  the  leaf.  Notice  the  drops 
of  moisture  that  gather  after  a  few  hours  on  the  inner  surface  of  the 
upper  tumbler.  Where  did  this  water  come  from?  Through  what 
part  of  the  leaf  must  the  water  pass  in  order  to  get  to  the  blade?  At 
what  points  does  the  moisture  get  out  of  the  leaf  into  the  air? 

EXERCISE  IX. — Experiment  to  locate  stomata. 

Materials. — Twigs  with  their  leaves;  boiling  water. 
Procedure. — Heat  some  water  to  boiling  and  plunge  the  end  of  a 
twig  into  it.    Notice  the  forming  of  gas  bubbles  at  the  stomata. 

EXERCISE  X. — Experiment  to  show  that  carbon  dioxide  is  given  off 
by  plants. 

Materials. — Leaves  of  clover,  alfalfa,  or  other  plants;  small  vial; 
lime-water;  air-tight  jar. 


38  HORTICULTURE  FOR  SCHOOLS 

Procedure. — Put  a  small  amount  of  water  into  a  quart  jar  having 
a  tight  cover.  Fill  the  jar  half  full  of  the  leaves.  Set  a  vial  of  lime- 
water  in  the  jar.  Fasten  the  cover  and  put  the  jar  in  a  dark  place  for 
twenty-four  hours.  A  scum  on  the  surface  of  the  lime-water  indicates 
the  presence  of  carbon  dioxide.  What  process  was  stopped  by  putting 
the  jar  in  the  dark? 

EXERCISE  XI. — Experiment  with  chlorophyll. 

Materials. — Test-tubes;  \vater;  alcohol;  benzol;   corks;  leaves. 

Procedure. — Place  a  leaf  in  a  little  water  in  a  test-tube  and  boil. 
Pour  in  alcohol,  and  heat.  The  solution  appears  green  and  contains 
chlorophyll  and  other  colored  substances.  To  separate  these  pour 
in  a  little  benzol.  Shake  thoroughly.  Place  a  cork  in  the  tube  and  let 
stand.  The  bluish  green  substance  is  chlorophyll;  the  other  substances 
are  yellow. 

EXERCISE  XII. — Exercise  to  show  the  presence  of  starch  in  leaves. 

Materials. — Alcohol;  leaves;  tincture  of  iodine. 

Procedure. — Extract  the  chlorophyll  from  a  leaf  with  alcohol  as  in 
the  preceding  exercise.  Mash  the  leaf  from  which  the  chlorophyll  has 
been  removed,  and  add  to  it  a  few  drops  of  dilute  tincture  of  iodine. 
A  blue  color  indicates  the  presence  of  starch. 


CHAPTER  III 
PROPAGATION  BY  SEEDS 

PLANTS  reproduce  themselves  (1)  sexually  by  means  either 
of  seeds  or  sex-spores,  or  (2)  asexually  by  buds  or  tissues 
capable  of  forming  buds,  or  by  vegetative  spores.  Some 
plants  depend  for  propagating  themselves  on  one  of  these 
methods  only,  while  others  multiply  by  both  sexual  and 
asexual  means. 

48.  Sexual  reproduction. — Two  kinds  of  organs  are  in- 
volved in  the  sexual  reproduction  of  plants;    stamens  and 
pistils.    The  stamens  produce  pollen-grains  which  fall  on  or 
are  carried  by  insects  or  wind  to  the  top  (stigma)  of  the 
pistil.    Under  favorable  conditions,  the  pollen-grain  on  the 
stigma  produces  a  tube  which  grows  down  to  the  egg-chamber 
(ovary)  at  the  bottom  of  the  pistil.    A  certain  nucleus  de- 
scends the  pollen-tube  and  unites  with  the  egg-nucleus  in  the 
ovary.    The  egg  is  then  said  to  be  fertilized.    As  a  result  of 
this  process,  seed  is  formed.1 

49.  Structure    of   the    seed. — A    seed    consists    of    the 
following : 

1.  The  embryo  or  rudimentary  plant,  which  is  capable 
under  proper  conditions  of  growing  into  the  mature  individual. 

2.  Cotyledons  or  seed-leaves  (one,  two,  or  in  some  cases 
more)  which  may  or  may  not  be  a  part  of  the  embryo. 

3.  Food  material  stored  either  in  the  cotyledons  or  outside 
of  them. 

4.  Protective  coats  or  coverings. 

1  The  process  is  explained  more  completely  in  Chapter  XII  on  pollination 
arid  fertilization. 

39 


40 


HORTICULTURE  FOR  SCHOOLS 


An  understanding  of  these  parts  can  best  be  obtained  by 
studying  certain  of  the  larger  seeds  under  a  magnifying  glass. 
Before  examination,  the  seeds  should  be  boiled  for  fifteen  or 
twenty  minutes  or  soaked  in  water  over  night.  Beans,  peas, 
corn,  and  pumpkin  seeds  are  especially  convenient  for  study. 

50.    The   pea    (Fig. 
20) . — Several  marks  are 
visible  on  the  outer  sur- 
face of  the  pea.  A  large 
\  scar,  called  the  hilum, 

PARJ  PRODUCED        marks  the  point  of  at- 
FROMxPLUMULE  ,     ,       ,,  , 

tachment  to  the  pod. 
At  one  side  of  the  hilum 
is  a  little  hole  known  as 
the  micropyle.  This  is 
the  point  where  the 
pollen-tube  entered  in 
the  fertilization  of  the 
ovule.  These  marks  be- 
long to  the  coat  of  the 
seed,  for  if  the  coat 
(testa)  is  removed  the 
marks  come  with  it. 
The  removal  of  the  coat 
disci  oses  two  thick  parts 
of  the  seed  (cotyledons), 
commonly  called  the  two 


PRODUfcED 
CAULICLE 


FIG.  20.— The  young  pea  plant.     Unlike  the  bean     halves  of  the  pea.     The 
the  cotyledons  stay  in  the  ground.     Notice  the 
plumule,    and    the   roots   developing    from    the 
caulicle. 


cotyledons  contain  a 
large  quantity  of  stored 
food  material  on  which  the  growing  plantlet  lives  until  it 
develops  roots  to  take  up  nourishment  from  the  soil  and  a 
foliage  system  to  manufacture  plant-food.  Attached  near 
its  middle  to  the  cotyledons  is  a  little  curved  body  (the 
embryo  of  the  pea),  of  which  one  end  (trie  caulicle)  will 


PROPAGATION  BY  SEEDS 


41 


--PLUMULE 
-CAULICLE 


COTYLEDON 


develop  into  the  root  system,  and  the  other  end  (the  plumule) 
will  form  the  stem  and  foliage  of  the  plant. 

When  the  pea  is  planted,  the  cotyledons  stay  in  the  ground 
and,  in  supplying  the  young  growing  plant  with  food,  they 
shrink  and  become  wrinkled.  The  plumule  pushes  its  way 
up  through  the  soil  to  form  the  stem  and  leaves  of  the 
plant,  while  the  caulicle  grows  downward,  forming  the  root 
system. 

51.  The  bean.— All  the 
parts  of  the  seed  found  in 
the  pea  are  present  in  the 
bean  (Fig.  21).  The  two 
little  leaves  in  the  plumule 
of  the  bean  can  be  seen 
clearly  with  a  small  magni- 
fying glass.  The  cotyledons, 
like  those  of  the  pea,  contain 
an  abundance  of  stored  food 
material  to  supply  the  young 
plant  until  it  becomes  estab- 
lished. The  growth  of  the 
bean,  however,  differs  from 
that  of  the  pea  in  several 
respects.  The  cotyledons  of 
the  bean  do  not  stay  in  the 
ground  but  are  brought  up  on  the  stem  into  the  air,  where  they 
turn  green  and  function  as  leaves  for  a  short  time  before  they 
finally  drop  off.  Some  botanists  consider  that  because  the 
cotyledons  function  for  a  time  as  leaves,  they  are  part  of  the 
embryo.  Others  think  that  they  are  not  part  of  the  embryo 
because  they  are  not  present  on  the  fully  developed  plant. 
In  the  bean  the  plumule  forms  the  part  of  the  top  above  the 
cotyledons,  while  the  caulicle  forms  both  the  root  system  and 
the  part  of  the  stem  extending  from  the  cotyledons  to  the 
roots. 


HILUM 
MICROPYLE 


FIG.  21. — The  bean  seed.  A,  Exterior  view 
of  bean;  B,  two  flat  surfaces  of  bean 
after  testa  has  been  removed. 


42 


HORTICULTURE  FOR  SCHOOLS 


52.  The  pumpkin  seed. — In  the  pumpkin  seed,  the  testa 
(outer  coat)  is  thick  and  hard,  and  when  it  is  removed  a  thin 

inner  green  coat  may  be  seen.  The 
cotyledons  are  thin,  flat,  and  large. 
When  the  seed  has  been  soaked, 
veins  in  the  cotyledons  show  dis- 
tinctly. The  thin  cotyledons  of 
the  pumpkin  seed  contain  a  much 
smaller  amount  of  stored  food  than 
is  present  in  those  of  the  pea  or 
bean;  therefore,  the  young  pump- 
kin plant  must  manufacture  plant- 
food  early.  It  does  this  by  bringing 
the  cotyledons  up  into  the  air  as 
soon  as  possible,  where  they  turn 

FIG.  22.— Germination  of  pumpkin  green  and  function  as  leaves  while 

the  true  leaves  are  forming.  As 
the  cotyledons  of  the  pumpkin 

remain  on  the  plant  permanently  and  act  as  leaves,  they  are 

part  of  the  embryo. 

The  pumpkin  seed  has  quite  a  struggle  to  free  itself  from 

the  tough  testa.    After  the  seed-coat  cracks  and  the  caulide 

projects,  a  protuberance  called  the  peg 

is  developed  at  just  the  right  place  on 

the  caulicle  to  catch  hold  of  the  split 

testa  in  such  a  manner  as  to  pull  it  off 

the  seed  as  the  cotyledons  are  drawn 

upward  (Fig.  22). 

53.  The  corn. — Another  type  of  seed 
is  represented  by  the  corn.     The  two 
sides  of  the  kernel  are  illustrated  in 
Fig.  23.     One  side  is  flat  and  smooth, 
while  the  other  has  a  slight  depressioa, 

lighter   in   color   than   the    surrounding    portions.     Under 
this  lies    the    embryo   and    the    cotyledon.     If  a   soaked 


FIG.  23. — Exterior  of  the  flat 
surfaces  of  a  kernel  of  corn. 
A  shows  the  slight  depres- 
sion under  which  lies  the 
embryo;  B,  the  opposite 
flat  side. 


PROPAGATION  BY  SEEDS  43 

kernel  of  corn  is  cut  longitudinally  the  narrow  way  of  the 
kernel  so  that  a  section  similar  to  the  one  shown  in  Fig.  24 
is  obtained,  the  parts  of  the  seed  can  be 
seen.  The  plumule  and  caulicle  can  be 
seen  easily  if  the  tip  of  each  is  raised 
with  the  point  of  a  knife  blade.  Sur-  I11F  ill. £J-U MULE 
rounding  the  plumule  and  caulicle  is  the 
cotyledon.  The  part  of  the  seed  to  the 
left  of  the  diagonal  line  in  the  illustra- 
tion is  not  part  of  the  cotyledon,  but  is 
stored  food  material  for  the  use  of  the 
young  growing  plant. 

54.  Two  classes  of  plants. — Plants  whose  seeds  have  two 
cotyledons,  such  as  the  pumpkin,  bean,  and  pea,  are  known 
as  dicotyledonous  plants,  while  those  whose  seeds  have  one 
cotyledon  are  said  to  be  monocotyledonous. 

In  the  plants  grown  from  dicotyledonous  seeds,  the  wood 
fibers  of  the  stems  are  arranged  in  circles  and  such  stems  are 
said  to  be  exogenous,  because  the  growth  takes  place  on  the 
outside  as  explained  in  paragraph  41.  Plants  of  this  type 
usually  have  netted-veined  leaves,  and  the  flower  parts  are 
in  fives  or  fours  or  their  multiples,  and  never  in  threes.  Most 
of  our  fruit-trees  belong  to  this  class. 

Plants  grown  from  monocotyledonous  seeds  have  endog- 
enous stems  with  the  wood  fibers  scattered  through 
them  as  explained  in  paragraph  41.  Such  plants  have 
parallel -veined  leaves,  and  the  flower  parts  are  usually  in 
threes  or  multiples  of  three.  All  true  grasses  belong  to  this 
type. 

It  will  be  seen  that  by  studying  the  seeds,  flowers,  stems, 
and  leaves,  it  is  not  only  easy  to  place  a  plant  in  the  correct 
class,  but  to  foretell  from  the  seed  what  kind  of  stem,  leaves, 
or  flowers  the  plant  will  be  likely  to  have;  or  to  tell,  by  ex- 
amining the  stem,  leaves,  or  flowers,  from  what  kind  of  seed 
any  plant  came. 


44  HORTICULTURE  FOR  SCHOOLS 

55.  How  plants  come  up. — Each  of  these  two  groups  of 
plants  has  its  own  method  of  coming  up  through  the  soil. 
The  young  monocotyledons  have  the  leaves  in  a  compact 
roll  ending  in  a  sharp  point,  which  is  forced  up  through  the 
soil  as  the  plant  grows.  After  the  leaves  are  through,  they 
gradually  unroll  and  spread  out.  On  account  of  the  manner 
in  which  the  leaves  come  through  the  soil,  monocotyledonous 
plants  can  get  a  start  in  very  heavy  compact  soils,  as  is  seen 
in  the  grasses. 

Because  of  the  large  size  of  the  leaves  and  the  manner  in 
which  they  are  folded  in  the  bud,  dicotyledons  cannot,  as  a 
rule,  successfully  push  their  tops  through 
the  soil,  especially  in  cases  in  which 
the  cotyledons  are  brought  out  of  the 
ground ;  therefore,  the  tops  of  such  plants 
are  pulled  up  by  means  of  the  stem 
(Fig.  25). 

56.  Seed  dissemination. -Nature  has 
provided  for  the  distribution  of  seeds 
by  various  methods.  Some  seeds,  as 
those  of  the  thistle,  milkweed,  cottonwood,  and  dandelion, 
are  provided  with  a  downy  covering  or  pappus  which  enables 
them  to  be  carried  long  distances  by  the  wind.  Seeds  of  the 
maple,  ash,  elm,  box-elder,  linden,  and  many  of  the  cone- 
bearing  trees  possess  wing-like  structures  which  enable  them 
to  sail  through  the  air  as  they  fall.  Seeds  which  float  easily, 
as  acorns,  nuts,  and  seeds  of  water  plants,  are  transported 
readily  by  running  water.  Water  from  irrigation  ditches 
frequently  spreads  weed  seeds  in  this  way.  Many  seeds  have 
sticky  coverings,  or  hooked  appendages,  which  enable  them 
to  hold  on  to  the  wool  and  hair  of  animals.  Beggar-ticks, 
stick-tights,  and  burdock  seeds  are  examples.  Some  seeds 
are  thrown  explosively  a  number  of  feet,  as  in  the  mistletoe. 
Many  pod-bearing  plants,  of  which  the  touch-me-not  is  an 
example,  throw  their  seeds  by  the  contraction  and  curling  up 


PROPAGATION  BY  SEEDS  45 

of  the  halves  of  the  pod.  In  the  squirting  cucumber,  the 
least  disturbance  of  the  plant  causes  the  cucumber  to  break 
loose  from  the  stem  and  shoot  its  seeds  with  considerable 
force. 

57.  Rest-period  of  seeds. — In  most  cases,  it  would  be 
fatal  to  the  life  cycle  if  seeds  were  to  grow  as  soon  as  shed, 
because  the  young  plants  might  be  brought  into  growth  at 
the  wrong  time  of  year  and  so  subjected  to  frost-injury  or  to 
other  unfavorable  conditions.    Nature  guards  against  this  by 
causing  the  seeds  to  go  into  a  resting  period  as  well  as  by 
requiring  certain  favorable  external  conditions  before  the 
seed  can  germinate.    Many  seeds  remain  in  the  resting  period 
for  a  considerable  length  of  time,  others  for  a  short  time,  while 
a  few  have  no  resting  period  at  all. 

58.  Storage  of  seeds. — Man  has  learned  to  preserve  seeds 
for  certain  lengths  of  time  by  providing  them  with  conditions 
which  will  keep  them  in  a  resting  state  without  injury. 

Seeds  with  thin  protective  coats,  including  those  of  most 
of  the  vegetables  and  cereals,  permit  of  air  drying  and  can 
be  preserved  by  storage  in  paper  bags  or  boxes  in  a  cool  dry 
place.  The  temperature  should  remain  as  nearly  uniform  as 
possible,  for  if  it  varies,  the  growing  power  of  the  seed  is 
likely  to  be  impaired.  The  best  temperature  for  storing  seeds 
in  temperate  climates  has  been  found  to  be  between  60  and 
70  degrees  Fahrenheit,  but  there  are  exceptions;  for  example, 
Indian  corn  keeps  best  in  a  temperature  near  the  freezing 
point. 

Seeds  with  thick  hard  coats,  such  as  nuts  and  pits  of  stone- 
fruits,  keep  best  when 
stratified.  Stratification 
consists  in  placing  seed 
and   sand  in  alternate 

layers  in  boxes  (Fig.  26) .  FIG.  26.— Stratification  of  seeds  in  box. 

The  sand  should  be  kept  slightly  moist  but  not  wet.  It  must 
be  coarse  enough  to  provide  drainage,  which  should  be  facili- 


i 


46  HORTICULTURE  FOR  SCHOOLS 

tated  by  the  boring  of  holes  in  the  bottom  of  the  box.  The 
box  should  be  covered  with  wire  netting  to  keep  out  mice  and 
other  animals  and  buried  with  the  top  about  four  inches  below 
the  surface  of  the  ground  in  well-drained  soil,  preferably  on 
the  shady  side  of  a  building.  It  is  well  to  have  the  stratified 
seed  exposed  to  weather  action,  for  in  cold  climates  frost  and 
moisture  crack  the  shell,  and  in  warm  climates  warmth  and 
moisture  soften  and  split  the  shell  so  that  at  the  proper  time 
the  seeds  can  sprout.  Some  nurserymen  stratify  large  quan- 
tities of  seeds  in  pits.  The  principle  is  the  same  as  when 
boxes  are  used.  Apple  and  pear  seeds  and  others  of  a  similar 
nature  should  not  be  allowed  to  dry  out,  but  should  be  strati- 
fied as  soon  as  freed  from  the  pulp.  Apple  and  pear  seed  are 
frequently  stored  and  shipped  in  powdered  charcoal.  They 
should  be  kept  in  a  cool  place,  an  ice-house  being  very  suitable. 

59.  Germination    of    seeds. — For    the    germination    or 
sprouting  of  the  seeds,  it  is  necessary  that  they  be  viable, 
and  that  certain  favorable  external  conditions  be  present. 

60.  Viability. — When  a  seed  possesses  the  power  to  grow 
under  proper  conditions  into  a  mature  plant,  it  is  said  to  be 
viable.     A  number  of  factors  affect  the  viability  of  seeds, 
such  as  the  maturity  of  the  seed,  climatic  conditions*  age  of 
the  seed,  methods  of  storing,  and  mechanical  injury. 

It  is  necessary  that  the  seed  be  mature.  Immature  seeds 
lose  their  viability  quickly  when  stored,  and  should  they 
germinate,  the  resulting  plants  are  likely  to  be  weak  and  to 
succumb  readily  to  disease. 

Seasons  or  climates  in  which  the  weather  is  fairly  uniform 
from  blossoming  to  harvesting  time  are  favorable  for  the 
production  of  good  seed.  Early  fall  frosts  or  wet  weather 
during  harvesting  are  very  detrimental.  Tropical  climates 
are  unfavorable  to  the  production  of  good  seed. 

The  viability  of  seed  is  affected  by  age.  This  is  due  to  the 
fact  that  during  the  normal  resting  period  of. seeds,  certain 
physiological  processes  go  on.  These  life  processes  are  slight, 


PROPAGATION  BY  SEEDS  47 

but  are  present  nevertheless.  After  a  time,  however,  a  point 
is  reached  where  the  life  processes  cease,  and  the  cells  of  the 
embryo  lose  their  power  to  grow  and  multiply  even  when 
placed  under  favorable  conditions.  The  length  of  time  seeds 
retain  their  viability  varies  with  the  kind  of  seeds  as  well  as 
with  the  conditions  under  which  they  are  matured  and  stored. 
Mechanical  injury  received  in  threshing,  or  due  to  the 
eating  of  parts  of  the  seed  by  insects,  may  result  in  inability 
of  the  seeds  to  germinate. 

61.  External    conditions. — The    presence    of    moisture, 
warmth,  and  oxygen  are  the  external  requirements  for  the 
germination  of  seeds. 

62.  Moisture. — The  first  process  in  germination  is  the 
absorption  of  the  proper  amount  of  water.    The  presence  of 
moisture  is  necessary  because  food  materials  can  be  trans- 
ferred from  part  to  part  only  when  in  solution.    The  water 
renders  possible  the  action  of  enzymes  (ferments)  always 
present  in  the  seed.    By  action  of  the  enzymes,  the  stored 
food  material  is  converted  into  the  forms  needed  for  the 
growth  of  the  embryo.    While  the  amount  of  water  most 
suitable  for  germination  varies  with  different  seeds,  usually 
enough  should  be  present  to  keep  the  seed  saturated,  but  not 
enough  to  exclude  the  air. 

63.  Oxygen   is  necessary  for  the  growth  of  the  embryo 
plant.    Enough  oxygen  is  present  in  the  soil  for  the  germina- 
tion of  seeds  unless  the  soil  is  water-soaked. 

64.  Heat. — A  certain  amount  of  warmth  is  necessary 
before  seeds  will  germinate.     Each  kind  of  seed  has  an 
optimum  temperature  at  which  it  germinates  best.     It  has 
also  a  minimum  and  maximum  temperature,  the  lowest  and 
highest  at  which  it  will  germinate .   The  optimum  temperature 
for  germination  usually  is  a  very  few  degrees  (1  to  4  degrees) 
higher  than  the  temperature  at  which  the  plant  makes  its 
best  growth.    From  60  to  80  degrees  F.  is  satisfactory  for  the 
germination  of  most  seeds,  but  there  are  exceptions.    Seeds 


48  HORTICULTURE  FOR  SCHOOLS 

of  many  tropical  plants  germinate  at  100  degrees  F.,  while 
those  of  some  maples  germinate  just  above  the  freezing  point. 
Seeds  with  thick  hard  shells  generally  require  higher  tem- 
peratures than  those  with  thin  coats. 

65.  Media  for  germination. — Seeds  will  germinate  in  any 
material  in  which  sufficient  amounts  of  heat,  moisture,  and 
oxygen  can  be  maintained,  provided  there  are  no  injurious 
(toxic)  substances  present.  In  nature  the  soil  is  the  medium 
for  germination. 

For  study,  seeds  can  be  germinated  in  boxes  of  soil  or  sand 
in  a  room  where  the  proper  temperature  is  maintained,  or 
outdoors  if  the  time  of  year  and  climate  permit.  Sawdust 
(not  oak  or  redwood  sawdust)  is  a  clean  and  convenient 
medium  in  which  to  grow  seeds  for  study  purposes.  The 
sawdust  can  be  placed  in  small  boxes  or  flats  and  should 
be  kept  moderately  moist  (not  wet)  and  at  the  correct 
temperature. 

Seeds  may  be  germinated  by  rolling  them  up  in  sheets  of 
blotting  paper,  or  newspaper.  The  roll  can  be  tied  with  a 
string  or  rubber  band  and  should  then  be  dampened  and 
stood  on  end  in  a  jar  containing  a  little  water.  The  water 
rises  in  the  roll  and  keeps  the  seed  moist.  By  placing  the 
seeds  in  rows  across  the  roll,  a  large  number  of  samples  can 
be  tested  at  the  same  time. 

Another  kind  of  germinator  can  be  made  by  placing  sheets 
of  blotting  paper  in  a  platter,  placing  the  seeds  between  the 
moist  blotting  papers,  and  covering  with  a  similar  dish  to 
retain  the  moisture. 

Small  seeds  may  be  germinated  by  placing  them  on  moist 
blotters  in  a  saucer,  and  covering  them  with  an  inverted  "• 
tumbler.    When  thus  placed,  they  may  be  examined  at  any 
time  without  being  disturbed. 

Germination  tests  are  useful  in  determining  the  value  of 
seeds  for  planting  purposes.  If  they  do  not  sprout  within  the 
proper  time,  they  are  without  vitality  and  are  quite  worthless. 


PROPAGATION  BY  SEEDS  49 

The  fact  that  the  seeds  sprout,  however,  does  not  show  that 
they  are  sufficiently  viable  to  produce  mature  plants,  but 
indicates  merely  that  they  have  not  lost  all  vitality. 

66.  Adulterated   seed. — Sometimes   inert    material,   old 
seeds,  and  other  seeds  resembling  those  desired  are  mixed 
with  good  seed.    Inert  material  and  seeds  of  different  kinds 
can  be  detected  by  examining  them  with  a  microscope.    Ger- 
mination tests  will  reveal  the  presence  of  old  seed.    Sometimes 
they  can  be  told  by  their  color. 

67.  Special  methods  of  causing  seeds  to  germinate. — 
Certain  seeds  are  benefited  by  special  treatment.    The  value 
of  stratification  in  softening  and  cracking  hard  shells  has 
been  mentioned. 

Soaking  for  a  few  hours  in  water  to  hasten  germination  is 
practiced  with  pear  and  apple  seeds,  corn  and  many  vegetable 
seeds.  The  soaking  should  be  stopped  as  soon  as  the  seeds 
have  swollen,  and  the  planting  should  take  place  immediately. 

Seeds  having  hard  thick  coats  may  be  treated  by  scalding. 
Boiling  water  should  be  poured  over  them  and  allowed  to 
cool.  The  seeds  should  remain  in  the  water  until  they  show 
signs  of  swelling.  Seeds  of  the  canna,  certain  locusts,  a  few 
conifers,  and  the  Kentucky  coffee-tree  are  examples  of  seed 
treated  in  this  manner. 

Many  seeds  with  hard  coats  are  benefited  by  being  soaked 
in  acids.  Clover  and  alfalfa  seed  are  soaked  in  sulfuric  acid 
for  a  few  minutes,  and  then  washed  thoroughly  in  water. 
When  it  is  necessary  in  plant-breeding  to  plant  the  seeds  of 
the  blackberry,  raspberry,  or  dewberry,  soaking  them  a  short 
time  in  vinegar  is  advisable.  Seeds  of  the  sweet-flag,  pond- 
lily,  arrowhead,  cat-tail,  and  many  of  the  sedges  are  benefited 
by  weak  acid  treatments. 

Mechanical  treatments,  such  as  filing,  grinding,  or  clipping, 
are  practiced  on  some  hard-coated  seeds  (among  which  are  the 
wild  cucumber,  canna,  and  olive)  as  an  aid  to  the  entrance  of 
water.  A  portion  of  the  coat  is  removed  down  to  the  embryo. 


50  HORTICULTURE  FOR  SCHOOLS 

68.  Planting  seeds. — While  proper  depth  of  planting 
depends  on  the  soil  and  kind  of  seed,  as  a  general  rule  it  is 
safe  to  plant  seeds  at  a  depth  four  times  as  great  as  their 
diameter.  They  must  be  deep  enough  to  escape  drying  out, 
but  should  not  be  so  deep  as  to  have  difficulty  in  forcing  their 
tops  through  the  soil. 

Seeds  may  be  planted  in  the  greenhouse,  in  boxes  known  as 
flats,  in  hotbeds,  or  in  the  field.  If  flats  are  used,  they  should 
not  be  too  large.  Flats  3  to  5  inches  high,  12  inches  wide, 
and  18  inches  long  are  convenient  to  handle.  Another 
satisfactory  size  is3xl8x!8  inches.  It  is  advisable  to  put 
some  gravel  in  the  bottom  of  the  flats  to  provide  drainage. 
The  remainder  of  the  box  should  be  filled  with  garden  loam. 
A  good  soil  for  this  purpose  is  made  by  mixing  leaf -mold  or 
rich  loam  with  clean  sand  in  about  equal  proportions,  to 
which  is  sometimes  added  1  or  2  per  cent  of  ground  bone. 
Seeds  are  planted  at  the  proper  depths  in  the  flats.  Very 
small  seeds,  like  those  of  the  petunia,  may  be  sown  upon  a 
thin  layer  of  powdered  sphagnum  moss  placed  upon  the 
surface  of  the  soil  in  the  flats. 

Seeds  are  frequently  planted  in  hotbeds  (see  Plate  I). 
Here  heat  is  furnished  by  fermenting  material  placed  in  the 
ground.  Usually  a  hole  is  dug  about  two  and  one-half  feet 
deep  and  of  an  area  equal  to  the  size  of  the  desired  hotbed. 
Into  this  is  put  horse-manure  and  grass,  which  are  kept  moist 
and  allowed  to  ferment  for  a  few  days  until  the  temperature 
goes  down  to  a  safe  point.  TJien  the  hole  is  filled  with  soil 
and  the  seeds  planted.  Over  the  bed  is  placed  a  frame  with 
a  glass  covering. 

A  good  sandy  soil  thoroughly  cultivated  and  leveled  is 
best  for  seeds  which  are  to  be  planted  in  the  open.  The 
seeds  are  planted  at  the  proper  depth  in  rows  and  covered 
with  soil.  After  the  seeds  are  planted,  the  soil,  unless 
heavy,  should  be  compacted  with  the  foot,  board,  or  roller 
in  order  to  bring  the  seed  in  contact  with  the  moisture. 


PROPAGATION  BY  SEEDS  51 

69.  Time  of  germination. — The  time  required  for  germi- 
nation varies  with  the  kind  of  seed  from  a  few  days  to  a  month 
or  more,  a  fact  which  must  be  taken  into  account  in  the  plant- 
ing.   Nursery  catalogues  and  books  on  gardening  frequently 
give  the  time  required  for  germination  of  various  seeds. 

70.  Transplanting. — Young  plants  are  sometimes  started 
in  the  greenhouse,  and  later  planted  out-of-doors.    They  may 
be  transplanted  from  flats  or  hotbeds  into  coldframes  before 
they  are  set  out  in  the  field.    Coldframes  are  similar  to  hot- 
beds except  that  no  heating  material  is  used.    The  sun  shines 
through  the  glass  frame  during  the  day,  warming  the  bed, 
and  at  night  the  covering  keeps  the  heat  from  radiating  too 
rapidly  and  prevents  frost  from  injuring  the  plants.    Some- 
times young  plants  are  placed  in  pots  and  set  out-of-doors 
before  being  planted  in  the  open,  or  repotted  into  larger  pots 
from  small  ones. 

EXERCISES 

EXERCISE  I. — Structure  of  seeds. 

Materials. — Seeds  of  corn,  pumpkin,  bean,  pea,  and  other  plants; 
knife;  dissecting  pin;  magnifying  glass. 

Procedure. — Prepare  seeds  in  the  manner  suggested  in  paragraph  49. 
Locate  in  each  the  hilum,  micropyle,  cotyledons,  plumule,  and  caulicle. 
Classify  the  seeds  examined  into  monocotyledonous  and  dicotyledonous 
seeds.  Prepare  a  table  showing  wherein  the  seeds  examined  are  alike 
in  structure  and  wherein  they  differ.  Make  outline  drawings  of  a  few 
types  of  the  seeds  examined,  labeling  the  parts. 

EXERCISE  II. — Growth  of  the  plant  parts. 

Materials. — Seeds  similar  to  those  studied  in  the  preceding  exercise; 
small  boxes;  sawdust  or  clean  sand. 

Procedure. — Plant  seeds  in  boxes  filled  with  sand  or  sawdust  kept 
moist,  and  dig  up  some  every  few  days  to  determine  the  manner  of 
growth  of  the  parts.  Observe  what  parts  of  the  plant  the  plumule 
and  caulicle  become.  What  becomes  of  the  cotyledons  in  each  case? 
Write  your  observations  as  to  how  plants  grow  and  illustrate  with  out- 
line drawings. 


52  HORTICULTURE  FOR  SCHOOLS 

EXERCISE  III. — Effect  of  temperature  on  plant  growth. 

Materials. — Seeds;  small  boxes;  sawdust,  sand,  or  soil. 

Procedure. — Plant  the  same  kinds  of  seeds  as  were  used  in  the 
preceding  experiment  in  several  boxes  of  sand  or  sawdust.  Supply 
each  box  with  the  same  amounts  of  moisture,  but  keep  them  at 
different  temperatures.  Note  the  difference  in  growth  at  the  various 
temperatures.  Write  your  conclusions  as  to  the  effect  of  these  tempera- 
tures on  growth. 

EXERCISE  IV. — Effect  of  moisture  on  the  growth  of  young  plants. 

Materials. — Same  as  in  preceding  exercise. 

Procedure. — Plant  seeds  in  boxes  in  the  same  manner  as  in  Exercise 
III.  Keep  the  boxes  supplied  with  different  amounts  of  water.  Note 
the  effects  of  the  different  amounts  of  water  on  the  germination  of  the 
seeds  and  the  growth  of  the  young  plants. 

EXERCISE  V. — Effect  of  soaking  seeds. 
Materials. — Peas,  corn,  and  other  seeds. 

Procedure. — Plant  some  seeds  which  have  been  soaked  for  a  few 
hours,  and  some  of  the  same  kinds  unsoaked.  Which  come  up  first? 

EXERCISE  VI. — Stratification. 

Materials. — Hard-coated  seeds  similar  to  those  mentioned  in  para- 
graph 58;  boxes;  soil. 

Procedure. — Stratify  some  hard-coated  seeds  in  the  manner  mentioned 
in  paragraph  58.  Note  when  they  sprout. 

EXERCISE  VII. — Seed  dissemination. 
Materials. — As  many  kinds  of  seeds  as  possible. 
Procedure. — Study  as  many  seeds  as  possible  to  determine  the  mode 
of  dissemination  of  each. 

EXERCISE  VIII. — Project  exercise. 

Materials. — Seeds  used  in  project. 

Procedure. — Students  are  requested  to  anticipate  at  this  time  the 
project  which  they  will  undertake  if  they  have  not  already  done  so. 
They  are  requested  to  secure  samples  of  seeds  which  will  be  utilized 
in  this  project  and  to  examine  them  in  the  light  of  facts  brought  out 
in  the  chapter.  Compare  the  seeds  with  those  already  examined, 
noting  as  closely  as  possible  all  similarities  and  differences.  Note  the 
length  of  time  it  takes  for  water  to  penetrate  these  seeds.  If  possible, 


PROPAGATION  BY  SEEDS  53 

keep  them  in  a  moist  warm  place  day  and  night  (for  example,  between 
sheets  of  moist  blotting  paper)  and  note  the  length  of  time  required 
for  germination.  Calculate  the  percentage  of  seeds  which  germinate. 
Divide  the  cost  for  a  pound  of  seeds  by  this  percentage  and  multiply 
by  a  hundred  in  order  to  ascertain  the  actual  cost  for  a  pound  of 
germinating  seeds. 


CHAPTER  IV 

ASEXUAL  PROPAGATION  OF  PLANTS  ON 
THEIR  OWN  ROOTS 

PLANTS  are  said  to  be  propagated  asexually  when  they  are 
grown  from  buds  or  from  tissues  capable  of  developing  buds. 
Some  plants  are  propagated  more  easily  asexually  than  by 
seeds.  Moreover,  many  kinds  when  grown  from  seeds  do 
not  come  true  to  type;  that  is,  they  do  not  resemble  the 
parent  plant  in  all  respects.  This  is  especially  true  of  the 
fruit-trees;  for  example,  if  a  seed  from  a  Bellflower  apple  is 
planted,  the  resulting  tree  is  prone  to  bear  apples  which  do 
not  resemble  those  borne  on  the  parent  tree.  In  asexual 
propagation,  on  the  other  hand,  the  resulting  plants  are  true 
to  variety. 

71.  Plants  on  their  own  roots,  and  on  the  roots  of  other 
plants. — Plants  are  propagated  asexually  on  their  own  roots 
by  such  systems  as  layering,  cuttings,  division,  and  separa- 
tion, and  on  the  roots  of  other  plants  by  budding  and 

grafting. 

72.  Layering. — One  of  the  easiest  methods  of  propagating 
plants  asexually  is  that  of  layering,  in  which  the  stems  are 
rooted  while  still  attached  to  the  parent.     The  process  is 
simple.    A  portion  of  a  branch  is  covered  with  soil  to  a  depth 
of  three  to  six  inches  to  keep  the  parts  moist.    With  many 
hardwood  plants  it  is  helpful  to  injure  the  part  from  which 
the  roots  are  to  form  by  ringing,  twisting,  or  cutting.    The 
part  is  staked  or  weighted  down  to  keep  it  in  place.   The 
following  are  some  of  the  methods  of  layering. 

54 


ASEXUAL  PROPAGATION  OF  PLANTS  ON  OWN  ROOTS  55 


73.    Tip  layering,  in  which  the  tips  only  of  branches  are 
placed  in  the  soil,  is  illustrated  in  Fig.  27.    The  black  rasp- 
berry and  loganberry  are 
propagated  in  this  way. 
74.  Simple  layering. — 
In  this  form  of  layering, 
the  branch  is  bent  over 
and  covered  with  soil  so        f 
as  to  leave  a  portion  of 
the  top   projecting,   as 
shown  in  Fig.  28.     Fre-     FlG  27-~Tip  layer' showing  early  growth  of  tip" 
quently  the  top  is  staked  in  order  to  keep  it  in  an  upright  posi- 
tion.   Usually  the  portion  buried  is  encouraged  to  form  roots 

by  wounding,  which  is  done 
by  scraping  the  bark,  cutting 
a  notch,  or  twisting.  Many 
varieties  of  plants  can  be  grown 
successfully  by  simple  layering. 
75.  Serpentine  or  compound 
layering  is  used  frequently 
when  it  is  desired  to  produce 
several  plants  from  a  single 
cane  or  vine.  In  this  form  of  layering,  the  branch  is  covered 
with  soil  at  various  points  where  there  are  buds  (Fig.  29); 


FIG.  28. — A  simple  layer. 


FIG.  29. — Serpentine  layer. 


56 


HORTICULTURE  FOR  SCHOOLS 


otherwise  it  is  treated  the  same  as  in  simple  layering.  Com- 
pound layering  is  much  used  with  vines. 

76.     Continuous  layering  (Fig.  30),  in  which  a  considerable 
length  of  the  stem  is  covered  with  soil,  leaving  the  tip  exposed, 

is  used  only  in  cases  of 
a  few  plants  such  as 
the  osier  and  snowball, 
which  produce  roots 
readily  from  the  buds. 
77.  Trench  layering 
is  used  in  propagating 

certain  varieties  of  grapes  and  other  vines  which  do  not  de- 
velop roots  readily  when  layered  in  the  ordinary  way.  The 
stem  is  pegged  down  in  a  shallow  trench  until  shoots  and 
roots  start  at  the  nodes.  Roots  can  be  induced  to  develop 
quickly  by  wounding  the  under  side  of  the  nodes.  A  little 
soil  is  finally  placed  in  the  trench. 

78.  Mound  layering  is  used  in   propagating   currants, 
gooseberries,  and  other  plants  hav- 
ing stiff  stems  which  are  difficult 

to  bend  over  and  layer  by  the 
usual  methods.  The  stems  are 
commonly  wounded  at  the  base 
and  mounded  up  with  soil 
(Fig.  31).  In  commercial  work, 
the  plant  is  generally  cut  back 
during  the  preceding  season  so 
that  many  new  shoots  are 
forced  out  to  give  a  large  number  of  shoots  for  layering. 

79.  Chinese  or  pot  layering  is  practiced  with  certain 
classes  of  shrubs  and  trees  having  stems  which  cannot  be 
bent  to  the  ground  readily.    Among  these  are  rubber  plants, 
crotons,  and  oleanders.    Portions  of  the  stems  are  wounded 
and  bound  in  sphagnum  moss.     Sometimes  specially  con- 
structed divided  earthen  pots  are  placed  on  the  wounded 


FIG.  31. — Mound  layer. 


ASEXUAL  PROPAGATION  OF  PLANTS  ON  OWN  ROOTS  57 

parts  and  filled  with  sand  or  other  material.  The  moss  or 
sand  must  be  kept  moist  by  frequent  watering  until  the 
roots  have  developed.  The  use  of  this  method  is  generally 
confined  to  the  greenhouse  or  situations  where  there  is  little 
danger  of  the  moss  drying  out. 

80.  Time  for  layering. — As  a  rule,  spring  is  the  best  time 
for  layering,  although  sometimes  it  is  performed  in  the  fall. 
Herbaceous  plants  of  a  succulent  nature,  such  as  geraniums, 
can  be  layered  in  summer,  when  it  is  difficult  to  grow  them 
from  cuttings.    After  layered  plants  have  rooted,  the  new 
individuals  are  cut  off  from  the  parent  and  set  out,  in  some 
instances  in  the  fall,  but  in  most  cases  in  the  following 
spring.    Some  plants,  however,  such  as  the  spirea,  tajje  two 
years  to  root,  from  the  time  they  are  layered. 

81.  Runners. — Plants  which,  like  the  strawberry,  produce 
runners,  are  propagated  by  a  sort  of  modified  layer.    From 
the  runners,  new  individuals  are  formed  which  may  be  cut  off 
and  set  out.     Plants  of  this  type  are  easy  to  propagate. 

82.  Cuttings. — Propagation  by  cuttings  consists  in  re- 
moving and  planting  certain  portions  of  plants.     Cuttings 
may  be  made  from  leaf,  stem,  tuber,  root,  or  bulb,  the  parts 
most  suitable  differing  with  the  species.     A  cutting  must 
contain  living  tissue  and  be  able  to  multiply  its  cells;    it 
must  have  a  growing  bud  or  be  able  to  produce  one;  and  it 
must  contain  enough  stored  food  to  keep  up  its  life  processes 
while  it  is  forming  roots  to  enable  it  to  take  up  food  material 
from  the  soil.    Cuttings  require,  for  their  growth,  moisture, 
hfftt,  oxygen,  and  light  in  amounts  varying  with  the  nature 
of  the  plant,  and  must  be  placed  in  a  suitable  medium  until 
the  roots  develop. 

With  most  plants,  the  cuttings  must  go  through  a  callus- 
ing  process  before  roots  form.  The  callus  is  simply  a  growth 
of  cells  formed  from  the  normal  growing  tissue  of  the  cutting. 
In  the  hardwood  cutting  in  Fig.  32,  the  callus  will  be  seen  as 
a  rim  proceeding  from  the  cambium  layer  at  the  cut  surface. 


58 


HORTICULTURE  FOR  SCHOOLS 


Roots  do  not  usually  develop  from  the  callus,  but  callus 
formation  generally  must  precede  root  formation. 

83 .  Leaf  -  cuttings. — Some 
plants  possessing  thick  fleshy 
leaves  with  an  abundance  of 
stored  food  can  be  propagated 
by  leaf-cuttings.  Leaves  of 
Bryophyllum  placed  on  moist 
sand  in  the  cutting-bed  will  pro- 
duce plants  from  the  notches 
in  the  leaves  (Fig.  33).  Most 
leaves  have  to  be  wounded  in 
order  to  be  able  to  send  out 
shoots  in  this  manner.  The  Rex 
begonia  leaf  will  produce  plants 
if  its  ribs  are  wounded  and 
it  is  pegged  down  in  sand.  It 
is  not  necessary  to  use  the  whole 
leaf,  a  piece  planted  edgewise  being  sufficient.  In  the  same 
way,  tomato  leaves,  if  the  bud  at  the  base  is  included,  will 
produce  plants.  Other  kinds  which  may 
be  propagated  in  this  manner  are  the 
cabbage,  rose,  lemon,  and  lilac,  but  few 
are  so  reproduced  commercially.  Leaf- 
cuttings  produce  plants  true  to  variety 
except  that  they  do  not  transmit  the 
irregular  white  or  yellow  spots  or 
blotches  on  leaves  known  botanically 
as  variegations. 

84.  Tuber -cuttings. —  Tubers  are 
thickened  underground  stems  having  an 
abundance  of  stored  food,  and  pos- 
sessing buds  capable  of  producing  plants. 
The  stems  grow  from  the  buds  or  eyes, 
and  from  the  stems  roots  develop.  When  a  portion  of  the 


FIG.  32. — Callusing  of  cuttings.  In  the 
longitudinal  section  the  callus  orig- 
inating at  the  cambium  has  forced 
out  the  several  layers  of  bark. 


FIG.  33.— A  leaf-cutting. 


ASEXUAL  PROPAGATION  OF  PLANTS  ON  OWN  ROOTS  59 

tuber  is  cut  off  so  as  to  contain  one  or  more  eyes,  and  is 
planted,  new  individuals  result.  The  Irish  potato  may  be 
propagated  in  this  way. 

85.  Root-cuttings. — Plants  which  naturally  produce  suck- 
ers1 from  the  roots  or  which  have  the  power  of  producing 
adventitious2  buds  from  the  roots  can  be  prop-  ~ 
agated  successfully  by  root-cuttings.  The  black- 
berry (Fig.  34),  red  raspberry,  horse-radish,  and 
Rosa  rugosa  are  propagated  commercially  in 
this  way.  Many  other  plants,  among  them 
willows,  poplars,  osage  orange,  juneberry,  plums, 
and  cherries,  can  be  propagated  by  root -cut- 
tings, although  most  of  these  are  reproduced 
more  easily  by  other  methods. 

Roots  for  cuttings  should  be  neither  too  large 
nor  too  small.  As  a  rule,  they  should  be  at 
least  as  large  as  a  lead  pencil,  but  not  over 
three-fourths  of  an  inch  in  diameter.  They  are  Flcut3ttn7?f0t0he 
cut  into  lengths  varying  from  one  to  four  inches. 
Root-cuttings  may  be  stored  in  sand,  and  kept  moist  in  a 
cool  place  until  they  form  a  callus.  In  the  spring  they  may 
be  removed  and  planted  out-of-doors.  Root-cuttings  of 
plants  which  thrive  in  cool  climates,  such  as  blackberries, 
roses,  and  lilacs,  can  usually  be  grown  out-of-doors.  The 
more  tender  plants  require  bottom  heat.  In  any  case  bot- 
tom heat  hastens  callusing.  When  root-cuttings  are  planted 
out-of-doors,  the  soil  should  be  pressed  down  over  them 
firmly  but  they  should  not  be  covered  too  deeply,  seldom 
over  an  inch.  The  cuttings  must  have  moisture  and  in  many 
cases  must  be  shaded.  Root-cuttings  produce  plants  true  to 
variety  with  the  exception  that  they,  like  leaf-cuttings, 
frequently  do  not  transmit  variegations. 

1  Sucker  is  the  shoot  of  a  plant  from  the  roots  or  lower  part  of  the  stem; 
usually  very  rapid  in  growth  and  unfruitful. 

2  Adventitious  (as  a  botanical  term)  means  out  of  the  proper  or  usual  place. 


60  HORTICULTURE  FOR  SCHOOLS 

86.  Stem-cuttings. — Cuttings     made     from     stems    or 
branches  must  be  planted  right  side  up,  that  is,  with  the  end 
which  grew  nearest  to  the  root  downward  in  the  soil.    For 
convenience,  stem-cuttings  can  be  divided  according  to  the 
hardness  and  maturity  of  their  tissue  into  three  classes:   (1) 
hardwood,  mature  or  dormant  cuttings;  (2)  herbaceous,  soft- 
wood or  active  cuttings;  and  (3)  semi-hardwood  cuttings. 

87.  Hardwood  cuttings  (Fig.  35)  are  made  from  wood 
which  has  completed  its  growth  and  has  matured.    In  moist 

tropical  countries  certain  trees  may  be  propagated 
by  breaking  off  branches  and  planting  them  in 
the  ground.  In  climates  like  those  of  the  United 
States  and  Canada,  propagation  by  hardwood 
cuttings  requires  more  care.  There  is  a  great 
difference  in  plants  in  this  regard;  for  example, 
pieces  of  the  olive  tree  split  into  cordwood  will 
produce  roots  and  foliage  if  one  end  is  placed  in 
moist  soil  while  it  is  still  green,  provided  that  a 
strip  of  living  bark  is  present.  Cotton  wood 
fence  posts  set  in  moist  soil  have  been  known 
to  develop  into  thriving  trees.  On  the  other 
hand,  cuttings  of  evergreen  trees  root  with 
difficulty. 

88.  Best  time  for  making  cuttings. — Hard- 
wo°d  cuttings  are  taken  either  in  the  autumn 
?afnthe  cur"  or  m  8PrmS-  Cuttings  made  in  the  spring 
are  usually  planted  in  the  field  immediately. 
Fall  cuttings  may  be  stored  over  winter  for  spring  planting 
or  in  mild  climates  may  be  planted  at  once  in  the  field.  Fall 
planting,  however,  even  in  mild  climates,  involves  risks. 
Cuttings  of  grapes,  for  example,  are  likely  to  rot  in  the 
winter  because  of  the  moisture  in  the  soil.  In  cold  climates, 
injury  to  the  wood  of  the  cutting  from  freezing  is  common. 
Hence,  in  general,  it  is  best  to  store  fall  cuttings  over  winter 
for  spring  planting.  They  may  be  stored  in  sand  or  sawdust 


ASEXUAL  PROPAGATION  OF  PLANTS  ON  OWN  ROOTS  61 

just  moist  enough  to  prevent  their  drying  out  and,  as  a  rule, 
should  be  kept  at  a  low  temperature  (just  a  little  above  the 
freezing  point)  in  order  to  keep  the  buds  from  starting.  Stor- 
ing over  winter  gives  opportunity  for  the  callus  to  form  and 
sometimes  for  the  roots  to  start  by  planting  time  in  the  spring 
so  that  the  stored  cutting  is  ahead  of  the  spring  cutting. 

Sometimes,  especially  with  hardwood  cuttings  difficult  to 
root,  bundles  of  them  are  buried  with  their  base  ends  upward 
just  beneath  the  ground  on  a  well-drained  knoll.  This  is 
usually  done  a  few  weeks  before  they  are  to  be  set  out  in  the 
spring.  The  sunshine  warms  the  upper  surface  of  the  soil, 
and  callusing  is  greatly  aided,  while  the  tops  of  the  cuttings 
are  down  in  the  cooler  portions  of  the  soil  and  the  buds  are 
kept  from  starting.  It  will  be  seen  that  this  method  is  simply 
a  means  of  securing  bottom  heat. 

89.    How  to  make  hardwood  cuttings. — Wood  of  the  pre- 
vious season's  growth  is  used  in  making  hardwood  cuttings. 
The  usual  and  convenient  length  for  these  cut- 
tings is  from  six  to   ten  inches.     The  cut  at 
the  base  end  is  usually  made  just  below   or 
through  a  bud  because  a  maximum  supply  of 
food  is   stored   at   that   point,  and,   therefore, 
callusing  takes* place  readily.    The  upper  end 
is  cut  about  half  an  inch  above  a  bud.    It  is 
customary  to  include  two  nodes  in  each  cut- 
ting, but  with  some  plants,  such  as  many  varie- 
ties of  grapes,  a  three-node  cutting  gives  best 
results.    When  cutting  wood  is  scarce  or  the  FIG. 36. -Single- 
nodes  are  so  far  apart  that  it  is  inconvenient  to      thl  Spe!g  ° 
have  two  nodes,  it  is  possible  to  make  single-eye 
cuttings,  as  illustrated  in  Fig.  36.     Single-eye  cuttings  are 
usually  placed  horizontally  in  sand  with  the  bud  uppermost, 
and  are  covered  to  a  depth  of  a  little  less  than  an  inch. 

In  planting  hardwood  cuttings  in  the  spring,  it  is  convenient 
to  dig  a  trench  and  set  up  the  cuttings  in  it  from  four  to  six 


62  HORTICULTURE  FOR  SCHOOLS 

inches  apart.  The  trench  should  then  be  filled  with  soil 
and  the  soil  packed  down  firmly  around  the  cuttings. 
When  the  earth  is  packed  tightly,  it  prevents  the  buds 
below  the  surface  from  producing  shoots.  Sometimes  all 
the  buds  except  those  which  are  to  be  left  above  ground 
are  removed.  Only  one  or  two  buds  should  project  out  of 
the  soil. 

90.  Cuttings  of  coniferous  plants. — Many  conifers  are 
propagated  by  hardwood  cuttings.  Small  cuttings  are  made 
of  the  mature  wood.  The  leaves,  except  those  at  the  lower 
end,  are  left  on.  The  cuttings  are  made  and  planted  in  the 
autumn  in  sand  in  a  cool  greenhouse.  They  are  slow  to  root. 
Spruce,  for  example,  generally  requires  over  a  year,  and  many 
other  evergreen  plants  need  one  or  two  years. 

91.  Softwood  cuttings  (Fig.  37).— Nearly 
all  plants  can  be  propagated  by  softwood 
cuttings.  Many  herbaceous1  plants  are 
propagated  in  this  manner  altogether.  As 
a  rule,  the  part  near  the  tip  of  the  branch 
or  stalk  makes  the  best  softwood  cutting. 
Material  for  softwood  cuttings  should 
not  be  taken  from  stems  that  have  al- 
ready formed  wood-fibers,  as  such  cut- 
tings  do  not  root  readily.  If  the  stem 
from  which  the  cutting  is  to  be  made 
breaks  when  bent  sharply,  it  is  suitable, 
FIG.  37.— Softwood  cut-  but  if  it  bends  without  breaking  it  should 

ting  of  the  carnation.    ^   ^    uged 

92.  How  to  make  softwood  cuttings. — The  base  end  of  the 
cutting  is  usually  cut  at  a  node,  although  in  some  instances 
better  results  are  obtained  by  cutting  between  the  nodes, 
owing  to  the  fact  that  the  tissues  at  the  nodes  have  hardened. 

1  An  herbaceous  plant  is  one  having  a  soft  or  succulent  stalk  or  stem,  that 
dies  to  the  root  every  year,  and  is  thus  distinguished  from  trees  and  shrubs, 
which  have  ligneous,  or  hard  woody  stems. 


ASEXUAL  PROPAGATION  OF  PLANTS  ON  OWN  ROOTS  63 

A  few  leaves  are  left,  but  most  of  them  should  be  removed  to 
lessen  transpiration.  Softwood  cuttings  should  usually  be 
quite  short. 

Softwood  cuttings,  as  a  rule,  should  be  kept  moist  from  the 
time  they  are  made  until  they  are  rooted.  It  is  true,  however, 
that  with  some  succulent  plants,  such  as  the  cactus  and 
geranium,  better  results  are  secured  by  allowing  the  cuttings 
to  wilt  before  they  are  planted. 

93.  Planting  softwood  cuttings. — The  greenhouse  is  the 
best  place  in  which  to  plant  cuttings  of  this  nature.    They 
should  be  placed  in  sand  which  should  be  packed  closely 
about  them.    Bottom  heat  is  desirable.    After  callus  forma- 
tions and  roots  begin  to  appear,  the  cuttings  may  be  trans- 
planted into  pots  or  into  flats  of  soil.    The  cuttings  should  be 
protected  from  bright  sunlight  during  the  hot  parts  of  the 
day. 

94.  Semi-hardwood  cuttings  are  made  from  those  parts 
in  which  wood  fibers  have  started  to  form.    They  are  used 
for  propagating  hardwood  plants.    Many  roses,  oleanders, 
hydrangeas,  and  the  like  can  be  propagated  successfully  by 
semi-hardwood  cuttings.     In  many  of  the  hardwood  plants, 
it  is  advisable  to  secure  at  the  base  of  the  cutting  a  heel  of 
the  older  and  harder  wood.     Sometimes  a  mallet-cutting  is 
made  for  the  same  reason.     These  cuttings  are  somewhat 
similar  to  a  mallet  in  shape,  the  short  cross-piece  being  of  the 
older  wood.     The   grape  is  often   propagated   by  mallet- 
cuttings. 

95.  Offsets. — Some   plants   produce   rosettes   of   leaves 
known  as  offsets,  which  are  in  fact  a  kind  of  bud.     These 
can  be  removed  and  set  in  soil,  where  they  root  readily. 
The  Cotyledon  (Echeveria)  is  an  example  of  a  plant  readily 
propagated  in  this  way.     Many  palms  are  propagated  by 
offsets. 

96.  Tuberous  roots. — Many  plants,  such  as  the  dahlia, 
which  produce  thickened  roots,  may  be  propagated  by  the 


64  HORTICULTURE  FOR  SCHOOLS 

planting  of  portions  of  the  roots  with  a  part  of  the  top 
attached. 

97.  Tuber. — The  distinction  between  a  tuber  and  tuberous 
roots  should  be  borne  in  mind.    The  latter  is  a  root  proper, 
but  a  tuber  is  a  thickened  underground  stem,  such  as  in  the 
potato  and  Jerusalem  artichoke.    The  so-called  eyes  of  the 
tuber  are  really  buds,  which,  when  removed  with  a  portion 
of  the  tuber  and  planted,  are  capable  of  producing  new  plants 
as  described  under  cuttings. 

98.  Bulbs  and  corms. — Bulbs  are  modified  buds.    Plants 
which  produce  bulbs  generally  have  a  short  growing  season 
and  a  long  dormant  season.     Bulbs  are  divided  into  two 
classes:   scaly  bulbs,  which  have  narrow  and  usually  fleshy 
scales,  loosely  arranged,  as  in  lilies;  and  tunicate  or  lam- 
inate bulbs  having  broad  scales   closely  fitting,  as  in  the 
onion. 

Bulbous  plants  produce  small  bulbs  at  the  bases  or  tops  of 
the  parent  bulbs,  or  among  the  bulb  scales.    They  are  propa- 
gated artificially  by  removing  the  small  bulbs  (bulbels)  and 
planting  them  at  the  proper  time.   Even 
the  thick  fleshy  scales  of  some  bulbs  may 
be  made  to  grow  by  being  removed  and 
treated  like  single-eye  cuttings. 

Small  bulbs,  usually  called  bulblets,  are 
sometimes  formed  on  the  stems  of  plants 
in  the  axils  of  the  leaves,  as  in  the  tiger 
lily,  or  in  the  flower-clusters,  as  in  the 
onion.  Bulblets  may  be  planted  in  the 
same  manner  as  the  ordinary  bulbs. 
dioiua  gro^Sg°aboSt  The  bulb  of  the  hyacinth  and  some  other 

old  corm.    Notice  the  .  ,  ,  ,  , 

cormeis  at  the  base  of     plants   may    be   made    to    produce,   by 
wounding,  more  small  bulbs  than  would 
otherwise  be  the  case. 

Corms  (Fig.  38)  are.  solid  bulbs  having  rings  of  compact 
tissue  instead  of  scales.     The  Indian  turnip,  gladiolus,  and 


ASEXUAL  PROPAGATION  OF  PLANTS  ON  OWN  ROOTS  65 

crocus  are  examples  of  plants  producing  corms.  Usually 
they  propagate  themselves  by  forming  a  new  corm  above  the 
old.  They  are  propagated  in  the  same  manner  as  bulbs. 

99.  Media  for  growth. — Sand  and  sawdust  have  been 
mentioned  as  suitable  media  for  starting  cuttings.    On  ac- 
count of  its  ability  to  hold  the  proper  amount  of  moisture, 
fairly  coarse  sharp  sand  is  most  generally  useful.     Very 
coarse  sand  does  not  hold  sufficient  moisture,  while  very  fine 
sand  contains  too  much  moisture  and  packs  so  closely  as  to 
interfere  with  the  supply  of  oxygen.     Therefore,  sand  of 
medium  texture  is  best.     In  order  to  lessen  the  liability  of 
disease,  there  should  be  no  organic  matter  present  in  the 
cutting-bed.    Sand  from  fresh  water  streams  is  good.    Sand 
from  any  sand-pit  may  be  used  with  safety  after  it  has  been 
exposed  to  the  action  of  weather  for  a  month  or  two.    A  con- 
venient way  to  cleanse  sand  for  the  cutting-bed  is  to  place 
it  in  a  water-tight  container  and  wash  it  with  a  stream  of 
water  from  a  hose  until  the  run-off  is  clear. 

100.  Temperature. — The  air  above  the  cutting-bed  should 
be  cool  enough  to  discourage  the  growth  of  the  tops  of  the 
plants  until  roots  form.     Sufficient  bottom  heat  should  be 
given  to  stimulate  the  growth  of  tissues.    The  bottom  of  the 
cuttings  should  be  kept  from  5  to  15  degrees  warmer  than 
the  air  above  ground,  especially  in  the  propagating  of  plants 
with  soft  tissue. 

101.  Apparatus  for  growing  cuttings. — Various  ways  of 
regulating  temperature  and  moisture  conditions  have  been 
devised.    A  few  kinds  of  cuttings,  such  as  those  from  olean- 
ders, will  produce  roots  if  the  cutting  is  kept  in  a  moderately 
warm  room  and  the  base  end  is  placed  in  a  bottle  of  water. 
Sometimes  a  small  unglazed  flower-pot  is  placed  inside  of  a 
large  one  and  the  spaces  between  are  filled  with  moist  sand 
in  which  the  cuttings  are  planted.    The  hole  in  the  bottom  of 
the  inner  unglazed  pot  is  plugged  and  the  inner  pot  is  filled 
with  water  which  seeps  through  gradually,  thus  keeping  the 


66 


HORTICULTURE  FOR  SCHOOLS 


FIG.  39. — A  simple  propagating  oven. 


sand  moist  at  all  times.  Propagating  ovens  (Fig.  39)  are 
small  cabinets  in  which  bottom  heat  is  provided  by  means  of 
a  lantern  or  other  heating  device  placed  under  a  pan  of 
water  above  which  is  the  sand  containing  the  cuttings.  Over 
the  top  of  the  cabinet  is  a  glass  sash  which  can  be  raised 

or  lowered  to  regulate 
the  temperature.  In 
hotbeds,  bottom  heat 
is  provided  by  fer- 
menting manure  and 
organic  matter.  By 
far  the  most  satisfac- 
tory arrangement  for 
rooting  most  cuttings 
is  the  cutting-bed  in 
a  greenhouse.  Sand  is 
placed  in  the  cutting- 
bed  and  bottom  heat  is 
furnished  by  steam  or  hot-water  pipes  running  under  the  bed. 
Ventilation  is  provided  so  that  the  proper  air  temperature 
above  the  plants  may  be  maintained.  Coldframes  are  some- 
times used  for  setting  out  cuttings 
previously  rooted  in  cutting -beds 
provided  with  bottom  heat.  This 
hardens  the  plants  and  prevents 
them  from  becoming  too  tall  and 
spindling.  Many  hardwood  cuttings, 
such  as  those  of  the  currant  and 
grape,  can  be  grown  by  planting 
them  out-of-doors  in  well-drained 
sandy  soil  (Fig.  40).  In  such  cases 
the  heat  of  the  sun  warms  the  soil 
but,  of  course,  the  heat  at  the  bot- 
tom of  the  plant  is  not  so  even  as 
that  in  cutting-beds  in  the  greenhouse.  Many  bulbs,  tubers, 


FIG.  40. — Method  of  plant- 
ing cuttings  in  a  trench. 


ASEXUAL  PROPAGATION  OF  PLANTS  ON  OWN  ROOTS  67 

and  tuberous  roots  will  start  to  grow  very  readily  out-of- 
doors. 

EXERCISES 

EXERCISE  I. — Propagation  by  cuttings. 

1.  Root-cuttings. 

Materials. — Knife;   roots  of  blackberry  or  similar  plants. 

Procedure. — Make  cuttings  from  two  to  six  inches  long.  The 
shorter  length  is  suitable  if  the  school  possesses  greenhouse  or  hotbed 
facilities.  The  longer  cuttings  should  be  made  if  they  are  to  be  grown 
out-of-doors.  The  cuttings  should  be  kept  during  the  dormant  season 
under  cool  and  moist  conditions  and  should  be  supplied  with  heat  as 
the  growing  season  approaches.  As  spring  approaches,  place  the 
cuttings  in  the  ground  about  three  inches  deep  and  keep  watered,  and 
cultivated. 

2.  Herbaceous  cuttings. 

Materials. — Herbaceous  plants;    cutting-bed;    or  place  out-of-doors. 

Procedure. — Make  some  leaf-  and  stem-cuttings  of  herbaceous  plants 
according  to  methods  described  in  the  text.  Plant  the  cuttings  in  sand 
in  flats  or  in  the  greenhouse,  or,  if  the  time  of  year  is  suitable,  out-of-doors. 

3.  Hardwood  and  semi-hardwood  cuttings. 
Materials. — Canes  of  currant  bushes,  or  grape  vines. 

Procedure. — If  the  cuttings  are  to  be  made  from  currant  bushes, 
wood  of  the  current  season's  growth  must  be  used.  Make  cuttings 
from  six  to  eight  inches  long,  following  the  suggestions  in  the  text  on 
hardwood  cuttings.  Store  the  cuttings  during  the  winter  in  the  manner 
mentioned  in  the  text.  They  must  be  kept  very  slightly  moist  and  be 
protected  from  heavy  frosts.  As  soon  as  the  weather  moderates  in  the 
spring,  place  the  cuttings  in  the  open  ground  with  the  upper  bud  just 
protruding  above  the  surface.  Pack  the  ground  tightly  around  the 
cuttings.  The  cuttings  will  root  readily  if  kept  cultivated  and  supplied 
with  moisture. 

EXERCISE  II. — Propagation  by  layering. 

Materials. — Black  raspberry  bushes;  grape  vines;  osier;  snowball; 
currants;  gooseberries. 

Procedure. — Layer  plants  according  to  methods  described  in  the 
text.  Keep  a  record  of  the  different  plants,  method  of  layering,  date 
of  layering,  and  conditions  under  which  they  are  layered.  Examine 
them  from  time  to  time  and  report  on  their  condition. 


68  HORTICULTURE  FOR  SCHOOLS 

EXERCISE  III. — Callus  formation. 

Materials. — Stored  or  planted  cuttings. 

Procedure. — Examine  cuttings  from  time  to  time.  Draw  a  callus. 
What  factors  are  necessary  for  callus  formation?  Which  of  the  cuttings 
examined  callus  most  readily? 

EXERCISE  IV. — Project:  If  the  student  is  contemplating  a  project 
involving  propagation  by  cuttings,  he  should  begin  a  systematic  study 
of  the  plants  he  intends  to  use  so  as  to  be  ready  with  cuttings  at  the 
opportune  time.  The  following  projects  are  suggested:  Propagating 
and  growing  blackberries,  raspberries,  currants,  loganberries,  goose- 
berries, strawberries,  or  ornamental  plants. 


CHAPTER  V 

ASEXUAL  PROPAGATION  ON  THE  ROOTS 
OF  OTHER  PLANTS 

PLANTS  are  propagated  on  roots  other  than  their  own  by 
means  of  budding  and  grafting,  which  consist  in  inserting 
a  part  of  one  plant  in  the  stem  or  root  of  another  with  the 
object  of  causing  the  two  to  grow  together.  The  portion 
of  a  plant  inserted  in  another  is  called  a  cion  (or  scion). 
The  plant  on  which  the  cion  is  placed  is  known  as  the  stock. 
Grafting  can  be  done  best  in  late  winter  or  early  spring 
when  the  tissues  are  in  a  resting  stage,  while  budding  is 
performed  in  late  spring,  summer,  or  early  autumn  when 
the  tissues  are  active. 

102.  Uses  of  budding  and  grafting. — By  means  of  bud- 
ding and  grafting  it  is  possible  to  perpetuate  varieties  which 
do  not  come  true  to  seed,  to  propagate  plants  which  do  not 
produce  sufficient  seed  or  which  do  not  grow  readily  either 
from  seed  or  by  asexual  methods  other  than  budding  or 
grafting,  and  to  adapt  plants  to  unfavorable  conditions  by 
the  use  of  suitable  stocks. 

103.  Limits   of   grafting   and   budding. — Commercially, 
grafting  and  budding  are  limited  to  exogenous  plants  of 
types  which  unite  readily.     Although  there  is  no  absolute 
rule  to  follow,  in  general  it  is  safe  to  say  that  the  closer 
the  botanical  relationship  the  more  certain  is  the  union. 
It  is  only  in  a  few  instances  that  it  is  possible  to  graft  mem- 
bers of  one  family  of  plants  upon  those  of  another.     One 
would  not  expect,  for  example,  that  the  peach,  a  member 
of  the  Rose  family,  could  be  grafted  upon  the  oak,  a  member 


70  HORTICULTURE  FOR  SCHOOLS 

of  the  Beech  family.  Members  of  different  genera  of  the 
same  family  may  or  may  not  unite.  For  example,  in  the 
Rose  family  it  is  possible  to  graft  some  kinds  of  pears  (genus 
Pyrus)  upon  the  quince  (genus  Cydonia),  but  it  is  not  pos- 
sible to  grow  the  apple  (genus  Pyrus)  upon  the  peach  (genus 
Prunus).  It  may  be  said  at  this  point  that  stone-fruits  will 
not  grow  on  pome-fruits  and  vice  versa.  Different  species 
of  the  same  genus  commonly,  though  not  always,  unite  suc- 
cessfully; for  example,  in  the  genus  Prunus,  the  peach 
(species  name  Persica)  can  be  united  with  the  common 
plum  (species  name  domestica).  Varieties  within  a  species 
commonly  unite  when  budded  or  grafted;  thus,  any  two 
varieties  of  peaches  will  unite,  or  any  two  varieties  of  apples. 
While  botanical  relationship  may  indicate  the  probabilities 
as  to  the  ability  of  any  two  plants  of  different  kinds  to 
unite,  experimentation  is  the  only  means  of  ascertaining  the 
facts  with  finality. 

104.  Essential  points  in  grafting  or  budding. — Success  in 
grafting  or  budding  depends  on  the  observance  of  the  follow- 
ing rules: 

1.  The  stock  must  be  suitable  to  the  cion. 

2.  The  operation  must  be  done  at  the  right  -time  of  year 
and  under  proper  conditions. 

3.  The  cambium  tissue  of  the  cion  must  be  in  contact 
with  the  cambium  of  the  stock. 

4.  The  wounds  must  be  prevented  from  drying  out. 

5.  Proper  attention  must  be  given  the  tree  after  graft- 
ing or  budding. 

105.  Budding. — Though  a  few  kinds  of  trees  are  better 
adapted  to  one  process  than  to  the  other,  in  general,  as  far 
as  propagation  itself  is  concerned,  it  makes  very  little  differ- 
ence whether  budding  or  grafting  is  employed.    The  choice 
of  method  will  depend  on  considerations  of  convenience. 
Budding  is  performed  during  the  growing  season.    Budding 
can  be  done  faster  than1  grafting,  and  more  trees  can  be 


ASEXUAL  PROPAGATION  ON  ROOTS  OF  OTHER  PLANTS  71 

budded  with  a  given  amount  of  cion  wood  than  can  be 
grafted.  These  are  important  considerations  when  many 
trees  are  propagated. 

106.  Types  of  budding. — Named  according  to  the  man- 
ner in  which  the   budding  is   performed,   the   kinds  are: 
shield-budding;    twig-  or  spur-budding;   flute-,   patch-,   or 
veneer-budding;     plate-budding;     and    ring-    or    annular- 
budding.     Shield-budding  is  by  far  the  most  common,  the 
other  methods  being  used  only  in  cases  where  shield-budding 
does  not  give  satisfaction. 

107.  Shield-budding. — The  main  steps  in  shield-budding, 
as  in  other  methods,  are : 

1.  Preparing  the  stock. 

2.  Selecting,  preparing,  and  keeping  the  bud-stick. 

3.  Cutting  the  stock  for  the  bud. 

4.  Removing  the  bud  from  the  bud-stick  and  inserting 
it  in  the  proper  place  in  the  stock. 

5.  Tying  the  bud.     . 

After-treatment    necessary  to  the   production  of  a  tree 
includes  the  following : 

a.  Cutting  the  ligatures  to  prevent  girdling. 

b.  Cutting  back  the  top  of  the  budded  tree  at  the  proper 
time  to  force  the  bud  into  growth. 

108.  Preparing  the  stock  previous  to  budding. — The  bark 
of  the  stock  should  peel  readily.     If  the  bark  is  tight  and 
does  not  peel,  it  is  advisable,  if  possible,  to  irrigate  the  rows 
a  few  days  previous  to  budding.    All  leaf  growth  and  suckers 
below  the  point  where  the  bud  is  to  be  placed  upon  the  stock 
should  be  rubbed  off,  but  this  should  be  done  not  longer 
than  three  days  before  budding  the  trees;    otherwise  the 
bark  is  likely  to  tighten. 

109.  Selecting  bud-wood. — Except  in  dormant  budding 
to  be  explained  later,  bud-wood  should  be  well-hardened 
wood  of  the  current  season's  growth.     It  should  be  taken 
from  bearing  trees  in  order  that  there  may  be  no  mistake  as 


72  HORTICULTURE  FOR  SCHOOLS 

to  the  variety  propagated.  Healthy  twigs  about  the  size  of 
a  lead-pencil  or  smaller  are  cut  from  the  tree,  wrapped  in 
moist  cloth  to  prevent  drying,  and  taken  to  a  shady  place 
for  the  preparation  of  the  bud-sticks.  In  the  preparation 
of  the  bud-stick,  the  leaves  are  cut  off  in  such  a  manner  as 
to  leave  a  small  portion  of  the  petiole  with  each  bud  as  is 
shown  in  the  illustration  (Fig.  44).  This  protects  the  bud 
as  it  is  pushed  down  in  the  bark  of  the  stock.  The  prepared 
bud-sticks  are  cut  into  convenient  lengths  and  placed  in 
bundles  with  the  large  ends  together.  The  bud-wood  should 
be  used  as  soon  as  possible,  but  may  be  kept  for  several 
days  if  stored  in  a  cool  place,  and  covered  with  moist  wrap- 
pings. In  some  instances  bud- wood  is  kept  for  several 
weeks.  Orange  bud-wood  is  frequently  stored  in  this  way 
in  moist  sphagnum  moss  wrapped  in  burlap.  The  bud- 
sticks  may  be  prevented  from  drying  out  in  the  field  by 
wrapping  them  in  moist  burlap  or  heavy  bags.  If  the  large 
ends  of  the  bud-sticks  are  near  the  open  end  of  the  wrap- 
ping, the  sticks  can  be  pulled  out  as  needed  without  dis- 
turbing the  remainder  of  the  bundle. 

The  part  of  the  twig  usually  possessing  the  best  buds  is 
shown  in  Fig.  44.  The  buds  near  the  tip  are  usually  spongy 
and  are  not  so  good  as  those  further  back.  The  buds  near 
the  base  of  the  twig  are  usually  not  well  developed  and 
hence  are  not  suitable. 

110.  The    operation    of    budding. — Individual    budders 
differ  in  many  minor  points  which  are  matters  of  personal 
preference,  but  the  main  parts  of  the  methods  are  the  same. 
The  following  is  a  description  of  one  of  the  methods  of  shield- 
budding. 

111.  Position. — Plate  II  shows  the  proper  position  for 
the  budder.    When  many  trees  are  to  be  budded,  the  budder 
usually  works  with  one  knee  on  the  ground  and  rests  his 
shoulder  over  the  other  knee  to  relieve  the  strain  on  his 
back. 


ASEXUAL  PROPAGATION  ON  ROOTS  OF  OTHER  PLANTS  73 


112.  Budding-knife. — The  budding-knife  should  be  very 
thin,  round  near  the  point,  and  of  the  best  steel  (Fig.  41). 
It  should  be  sharpened  on  a  fine  whetstone  and 

stropped  to  a  razor  edge  from  time  to  time  in 
the  field.  A  sharp  knife  is  one  of  the  essentials 
for  success  in  budding. 

113.  Cutting  the  stock. — The  size  of  stock 
most  convenient  is  about  that  of  a  lead-pencil, 
but  stocks  larger  or  smaller  can  be  budded. 
More  skill  is  required  to  bud  small  stocks  than 
large.     A  cut  from  one  to  one  and  one-half 
inches  long  is  made  parallel  with  the  sides  of  the 
tree  by  holding  the  knife  and  guiding  it  with 
the  finger  as  shown  in  Fig.  42.    A  cross-cut  is 
then  made   (Fig.  43)  with  a  slightly  rolling 
motion  of  the  knife  to  open  the  bark  for  the 
insertion  of  the  bud.    The  cuts  are  just  deep 
enough  to  go  through  the  bark.   Usually  the  cut 
should  be  on  the  side  of  the  tree  away  from  the 
sun  and  as  low  oil  the  stock  as  possible. 

114.  Inserting  the  bud. — The  bud  to  be 

inserted  in  the  stock  is  cut  from  the  bud-stick,  as  shown  in 
Fig.  44.    The  knife  is  steadied  by  holding  the  thumb  in  the 

position  indicated,  the  blade 
entering  below  the  bud  and 
coming  out  above.  The  part 
of  the  bud-stick  cut  out  with 
the  bud  is  known  as  the 
shield .  Care  should  be  taken 
to  have  both  ends  of  the 
shield  long  enough  to  keep 
the  bud  from  drying  out  after 
it  is  tied.  Usually  a  little  of 
the  wood  is  removed  with  the  bark.  Since  the  cambium  of  the 
bud  should  have  plenty  of  surface  in  contact  with  the  cambium 


FIG.     41.— A 
budding-knife. 


FIG.  42. — Making  the  longitudinal  incision 
preparatory  to  budding.  Note  the  posi- 
tion of  the  knife  and  forefinger. 


74 


HORTICULTURE  FOR  SCHOOLS 


FIG.  43. — Making  the  cross- 
cut of  the  "T"  with  a  rolling 
motion  of  the  knife. 


of  the  stock,  some  budders  prefer  to  take  out  the  wood,  leaving 
only  the  bark,  but  this  is  unnecessary  except  in  a  few  special 
cases. 

As  the  knife  comes  up  through  the  bark,  the  top  portion 
of  the  bud  is  grasped  between  the 
thumb  and  the  knife-blade  so  as  to 
be  in  position  (Fig.  44)  to  be  placed 
immediately  in  the  "T"  cut  in  the 
stock.  The  bud  is  inserted  and 
pushed  down  with  the  thumb  (Fig. 
45)  or  with  the  point  of  the  knife- 
blade.  The  tip  or  lower  end  of  the 
shield  should  be  pushed  a  little  way 
below  the  vertical  cut.  The  top 
should  not  come  above  the  cross- 
cut (Fig.  46)  because  any  portion 
projecting  could  not  unite  with  the  stock  and  would  prob- 
ably cause  all  of  the  bud  to  dry  out 
and  die.  With  a  little  practice,  the 
shield  can  be  cut  just  the  correct 
length,  but  if  it  should  be  too  long 
the  top  can  be  cut  off  with  the  knife 
after  the  bud  is  in  place. 

115.  Tying.— The  bud  must 
be  tied  firmly  in  order  that  the 
two  cambium  layers  may  be  held 
closely  together  and  the  bud 
prevented  from  drying  out.  Various 
materials  have  been  utilized  for 
tying,  but  string  is  to  be  preferred, 

especially  in  arid  climates.  Raffia  (consisting  of  fibers  of  a 
large  palm)  is  also  used.  When  raffia  is  employed,  it  should 
be  soaked  for  a  number  of  hours  and  tied  while  wet.  Fig.  47 
will  make  clear  the  manner  of  tying.  With  string  three 
wraps  are  usually  made  below  the  bud  and  four  above  it.  The 


ASEXUAL  PROPAGATION  ON  ROOTS  OF  OTHER  PLANTS  75 


important  point  in  wrapping  is  to  keep  the  string  tight,  and  to 
wrap  so  that  all  portions  of  the  bark  are  held  down  firmly. 

116.  Removing  the  ligatures. — In  order  to  prevent  gir- 
dling, in   about   ten   days  after 

budding  the  strings  are  cut  on 
the  side  of  the  tree  opposite  the 
bud. 

117.  Topping  the  budded 
trees. — When  it   is  desired  to 
force   out  the   bud,  the  top  of 
the  tree  is  cut  off  to  cause  the 

sap  and  food  material  to  go  to  FlG-  4o.-inserting  the  bud. 

the  bud.  Sometimes  the  top  is  cut  off  at  one  operation  to 
within  a  half  inch  of  the  bud.  Many  prefer  to  cut  off  a  part 
of  the  top  first,  so  as  to  avoid  shocking  the 
tree,  and  later  to  cut  back  to 
the  proper  distance.  When  it 
is  desired  to  produce  a  tree  the 
same  season  as  it  is  budded,  as 
in  June-budding,  topping  must 
be  performed  in  that  season, 
but  in  fall-budding,  since  it  is 
undesirable  to  have  the  buds 
forced  out  the  same  season, 
topping  is  not  done  until  the  FlSed47with  string. 

following  Spring.  The  string  is  tied 


118.     Other  forms  of  bud- 

Flfn8etteTTNotiir  ding.— While  shield-budding  is 
thf  buhd%Ci  is  the  common  form,  other  meth- 


tightly  and  is  held 
by  the  end  being 
pulled  under  the 
last  wind.  Al- 
though a  portion 
of  the  edges  of  the 
bark  shows  be- 
tween the  winds 
of  the  string,  the 
flaps  are  held 
down  securely  at 
all  parts. 


barknandntheat  the  ods  are  used  in  special  cases. 
ap  the6  edge  Spur-budding,patch-,andring- 
buddingareemployedon  thick- 
barked  trees  where  shield-budding  does  not  give  good  results. 
Twig-  or  spur-budding  differ  from  shield-budding  only  in  that 
a  spur  or  short  twig  on  which  there  is  a  bud  or  buds 


76 


HORTICULTURE  FOR  SCHOOLS 


is   left    on   the    shield   instead    of   the  single  bud.      (See 
Fig.  48.) 

119.  In  flute-,  patch-,  or  veneer-budding  a  rectangular 
piece  of  bark  is  removed  from  the  stock  and  replaced  imme- 
diately with  a  piece  of  bark  of  similar  size  and  shape  bearing 
a  bud  of  the  variety  to  be  propagated  (Fig.  49). 
There  are  special  devices  to  facilitate  the  cutting 
of  the  bark  to  uniform  size,  but 
an  ordinary  knife  can  be  used. 

120.  Ring-  or  annular-budding 
is  similar  to  flute-budding,  except' 
that  a  ring  of  bark  is  removed 
all  the  way  around  the  tree  and 

FIG.  48. — Twig-    .  -,          -,       . , ,  M 

budcutready  is  replaced  with  a  similar  ring  cut  FIG.  49.— Patch- 

for   insertion.     /.  .-,  budding.      A, 

irom  the  ClOn.  stock  prepared  for 

121.    In  H-budding  the  bark  of  the  stock  is     oTplece  oSkrf 
cut  as  shown  in  Fig.  50.    The  flaps  of  the  bark     p  a  tVk . s l&?t  h" 
are  raised,  and  a  piece  of  bark  from  the  cion     pat 
of  proper  size,  and  bearing  a  bud,  is  placed  so  that  its 
cambium  comes  in  contact  with  the  cambium 
of  the  stock,  and  the  flaps  are  bound 
over  it.    In  H-budding  arid  in  other 
special    methods,    in    addition    to 
tying  the  bark  in  place,  it  is  fre- 
quently of  advantage  to  wax  over 
the  cut  surfaces. 

122.  Chip-budding  is  much  used 
H-  on  dormant  stocks  when  the  bark 
will  not  slip.  In  this  form,  a  mortise 
is  made  in  the  stock  and  a  chip  containing  a  bud  cut  from 
the  cion  wood  is  forced  into  it.  (See  Fig.  51.)  The  chip 
is  tied  in,  and  when  above  ground  is  usually  waxed.  In 
chip-budding  on  grape  roots,  where  this  method  is  much 
used,  the  chip  need  not  be  tied  or  waxed  as  the  part  is 
covered  with  soil. 


FIG.  50.- 
budding. 


FIG.  51.— Chip- 
budding. 


ASEXUAL  PROPAGATION  ON  ROOTS  OF  OTHER  PLANTS  77 

123.  Fall-  and  June-budding. — In  fall-budding,  the  buds 
are  inserted  late  enough  so  that  they  do  not  produce  shoots 
the  same  season,  but  unite  and  remain  through  the  winter 
as  dormant  buds.     In  the  following  spring,  the  shoots  are 
forced  out.    It  takes  two  seasons  in  the  nursery  to  produce 
a  tree  by  this  method,  which  is  the  one  most  practiced. 

June-budding  must  be  performed  early  enough  to  give  the 
bud  time  to  produce  a  shoot  the  same  season.  It  is  possible 
to  obtain  a  salable  nursery  tree  in  one  season  by  this 
method. 

124.  Dormant-budding  is  practiced  when  it  is  desired  to 
bud  trees  just  as  soon  as  the  bark  slips  easily  in  the  spring. 
At  this  time  of  year  it  is  impossible  to  obtain  buds  from  the 
current  season's  growth.     Hence,  buds  must  be  -obtained 
from  the  last  year's  wood.    Such  wood,  however,  is  subject 
to  winter-kill  and  the  buds  may  be  injured  without  showing 
it  clearly.    On  this  account  the  bud-wood  is  taken  from  the 
tree  and  stored  over  winter  in  sawdust  or  sand  kept  very 
slightly  damp.    In  the  spring  just  as  soon  as  the  bark  slips, 
the  dormant  buds  are  cut  and  inserted  from  the  stored  cions 
exactly  as  in  the  case  of  June-budding. 

125.  Top-budding. — The  foregoing  methods  apply  espe- 
cially to  nursery  stock.    Sometimes  it  is  desired  to  bud  the 
tops  of  trees  to  certain  varieties.    In  that  case,  the  branches 
are  cut  back  to  force  out  the  young  shoots  and  the  budding  is 
done  on  these  shoots.    Usually,  however,  grafting  is  used  in 
top-working  trees. 

GRAFTING 

Grafting,  like  budding,  consists  in  inserting  the  cion  in 
the  stock  so  that  the  cambium  layers  come  in  contact.  In 
grafting,  however,  the  cion  usually  contains  more  than  one 
bud.  Grafting  may  be  done  while  the  trees  are  dormant,  in 
late  winter  or  early  spring  before  the  sap  starts  to 
circulate. 


78  HORTICULTURE  FOR  SCHOOLS 

126.  Parts  of  the  tree  which  are  grafted. — Grafts  may 
be  placed  on  the  roots,  crown,  stem,  branches,  or  tips  of  the 
branches. 

Root-grafting  is  much  used  in  propagating  nursery  stock. 
The  grafts  are  usually  made  by  the  whip  method1  on  roots 
previously  dug  and  stored  for  the  purpose. 

Crown-grafting  is  made  on  the  crown  of  the  tree  near  the 
ground,  usually  by  the  bark  or  the  modified  cleft  method. 
Large  crowns  »can  be  grafted  in  this  manner  and  trees  with 
damaged  tops  can  be  saved.  This  form  of-  graft  has  been 
employed  much  in  Europe  to  save  the  trees  damaged  during 
the  war.  Crown-grafting  by  the  cleft  method  is  used  on 
nursery  stock  also.  The  small  trees  are  cut  off  near  the 
ground  and  grafted. 

In  trunk-  or  stem-grafting,  the  whole  top  of  the  tree  is 
cut  off  and  the  cions  are  inserted  into  the  trunk. 

Branch-grafting  is  a  common  method  on  old  trees.  The 
branches  are  cut  off  where  they  are  of  convenient  size  (from 
1  inch  to  2  inches  preferred)  and  are  usually  grafted  by  the 
cleft  method. 

In  tip-grafting,  small  cions  are  grafted  on  the  twigs  near 
the  ends.  While  this  sort  of  grafting  is  difficult  to  perform 
satisfactorily,  it  is  coming  into  use  with  plant-breeders  who 
desire  to  test  out  new  varieties.  By  tip-grafting,  the  cion 
can  be  made  to  produce  fruit  more  quickly  than  in  any  other 
way. 

127.  Grafts  classified  according  to  manner  of  their  mak- 
ing.— Many  methods  of  grafting  have  been  devised.    Whip 
or  tongue,   cleft,   bark,   kerf,   veneer,   saddle,   bridge,   and 
inarching  or  approach-grafting  are  some  of  the  most  common 
forms. 

128.  Whip-  or  tongue-grafting  is  used  on  small  stocks.    It 
is  common  in  root-  or  bench-grafting.     The  stock  and  cion 
are  both  cut  obliquely  with  one  stroke  of  a  sharp  knife.    A 

1  See  paragraphs    127  to  137  for  a  discussion  of  the  various  methods. 


AS1 


ASEXUAL  PROPAGATION  ON  ROOTS  OF  OTHER  PLANTS  79 

slanting  cut  is  then  made  in  the  stock  and  cion,  as  shown  in 
Fig.  52,  and  the  two  parts  are  forced  together  as  illustrated. 
If  the  graft  is  made  properly,  no  light  should  show  through. 
The  tongues  should  not  pro- 
ject but  should  come  to  the 
position  shown  in  the  illus- 
tration. If  they  project, 
they  may  be  cut  off  to  the 
proper  length.  The  grafts 
are  wound  with  a  few  turns 
of  waxed  knitting  cotton 
which  breaks  easily,  so  as 
not  to  cause  girdling  when 
growth  takes  place.  In  com- 
mercial establishments,  the  ^ 
grafts  are  wound  by  a  ma-  FIG 
chine.  Many  propagators 
do  not  wind  the  grafts  at 
all,  but  fit  them  firmly  together.  If  whip-grafts  are  made 
on  parts  above  ground,  the  grafts  must  be  waxed  at  all 
cut  surfaces. 

129.    Cleft-graft  (Figs.  53-57).— This  is  one  of  the  oldest 

grafts.  It  is  used  for  the 
most  part  on  branches 
three-fourths  of  an  inch 
in  diameter  or  larger. 
The  branch  to  be  grafted 
is  first  sawed  off.  The 
stub  is  then  split  with 
a  grafting  tool  and  a 
wedge  put  in  to  keep  the 
cleft  open.  The  cion  is 
cut  obliquely  on  both  sides  as  shown  in  Fig.  55,  a  bud 
being  left  low  down  on  the  cion  just  above  the  place  where 
the  cut  surfaces  begin.  The  wedge  of  the  cion  is  left  a  little 


52.— Whip-grafting.  A,  stock  cut 
ready  for  cion;  B,  cion  cut;  [C,  graft  com- 
pleted; D,  graft  tied  with  waxed  yarn. 


Fio.  53.— Splitting  the 
stock  with  the  graft- 
ing tool  which  is  driv- 
en in  with  a  wooden 
mallet. 


80 


HORTICULTURE  FOR  SCHOOLS 


wider  at  the  outside  part  than  it  is  on  the  inside  portion. 
The  cion  is  inserted  as  shown  in  the  figure  in  such  a  manner 

that    its    cambium  and 
that  of  the  stock  come 
together  at  some  point. 
The    cion    should    be 
pushed  down  until  the  lowest  bud  is  even 
with   the   top   of   the   stock.     When  the 
wedge    is    removed   from   the    cleft,    the 
elasticity  of  the  stock  causes  the  cion  to 
be  held  firmly.     It  is  well  to  insert  two 
cions,  one  on  either  side  of  the  stub,  be- 


FIG.    54. — Opening  the 

cleft  for  the  insertion  cause   healing  takes   place   more   rapidly 
than 


of  the  cions. 


is  the  case  if  only  one  is  inserted. 
The  extra  cion  can  be  cut  out  later.  On  large  stubs  a  num- 
ber of  cions  are  often  used  to  facilitate  healing.  All  cut  sur- 
faces should  be  covered  with  grafting-wax, 
including  the  top  cut  surfaces  of  the  cions. 
Frequently  in  cleft-grafting,  which  is 
much  used  in  the  top-grafting  of  old  trees, 
the  stub  is  split  at  one  side  of 
the  center,  or  in  several  places, 
so  that  the  cleft  does  not  run 
through  the  central  portion  of 
the  tree.  As  the  clefts  can 
thus  be  made  smaller  than  if 
they  go  through  the  center, 
they  heal  faster. 

130.    Kerf -graft    or    inlay- 
j. — In  this  graft  a  triangular 
cutler  ins"er-  piece  is  cut  out  of  the  stock, 

tion    in   the  .    ' 

cleft.  usually  by  means  of  a  special 

tool,  the  base  of  the  cion  is  cut  to  fit,  and  is  inserted 
in  the  space  in  the  stock.  The  cion  must  be  tied 
firmly  in  place  and  waxed.  The  kerf -graft  is  preferred 


it  for  inser-    piece  IS   CUt  OUt    of    the    stock,        FIG.  56.— Cions  in- 
on   in  the    r  serted  in  cleft 

M-  usually  by  means  of  a  special        ready  for  waxing. 


ASEXUAL  PROPAGATION  ON  ROOTS  OF  OTHER  PLANTS  81 


by   many  to   the   cleft  for  stocks  having  a  pith  in   the 
center. 

131.  Bark-graft.  —  When  the  bark  will  peel,  large  stocks 
are  frequently  grafted  by  this  method.    The  stock  is  cut  off 
and  vertical  slits  are  made  in  the  bark 

where  the  cions  are  to  be  inserted.  The 
cions  are  cut  as  in  Fig.  58  and  the  tongues 
inserted  under  the  bark.  The  top  of  the 
stock  is  then  wrapped  tightly  with  string 
and  waxed  over. 

132.  Veneer-grafting  is  used  almost  en- 
tirely in  the  greenhouse.    A  shallow  notch 
is  cut  in  the  stock,  and  the  cion  is  fitted 
in  the  notch.     The  cion  is  tied  in  with 
raffia  and  the  grafted  plant  is  kept  in  the 
greenhouse  where  there  is  plenty  of  mois- 
ture in  the  atmosphere. 

133.  Side-grafting.—  In   this    graft   a 
cut  is   made   in  the  side    of    the    stock, 

and  the  cion,  trimmed  so 
that  its  base  is  wedge- 
shaped,  is  inserted  in  the 
cut.  Out-of-doors  the 
wounds  must  be  waxed. 
Side-grafting  is  much  used 
with  stone-fruits  like  the 
peach  (Fig.  59). 

134.  Saddle-grafting.—  In 
grafting  many  greenhouse 
plants,  the  stock  is  cut  in  the 
shape  of  a  wedge,  and  the  cion 
is  split  or  notched,  and  placed 

°ver  ^ne  Wedge. 

1^35        Inarching      01      ap- 

proach-grafting.  —  In  a  few  special  cases,  marching  is  useful. 


FIG.  57.— The  graft 
after  being  waxed. 


Fia.   58.—  Bark-graft,  showing  method  of 
cutting  cions  and  inserting  in  stock. 


82 


HORTICULTURE  FOR  SCHOOLS 


The  method  consists  in  uniting  two  plants  while  they  are  on 
their  own  roots.  A  piece  of  the  bark  is  cut  from  the  stems 
of  the  stock  and  cion  and  the  two  wounded  portions  are  tied 
tightly  together.  Waxing  is  necessary.  After  the 
union  has  taken  place,  the  top  of  the  stock  is  cut 
off  just  above  the  graft,  and  the  stem  of  the  cion 
just  below  the  graft,  leaving  the  top  of  the  cion 
on  the  stock. 

136.  Bridge-grafting. — Trees  which  have  been 
injured  by  being  girdled  by  rabbits  or  rodents 
can  frequently  be  saved  by  bridge-grafting.  This 
FIG.  59.— side-  form  is  also  useful  in  cases  in  which  pear-blight 
has  made  it  necessary  to  remove  portions  of  the 
tree  trunk.  In  bridge-grafting  the  bark  around  the 
edge  of  the  wound  is  first  trimmed  to  a  smooth  edge,  and 
the  ends  of  a  small  branch  of  the  proper  length  are  cut 
obliquely  and  inserted  under  the  edges  of  the  bark.  Such 
cions  are  placed  at  intervals  of  every  two  or  three  inches 
(Fig.  60).  Sometimes  the  ends  of 
the  inserted  cions  are  nailed  down. 
The  ends  of  the  cion  and  edge  of 
the  bark  must  be  waxed,  and  all  the 
injured  surfaces  should  be  painted. 
As  the  sap  circulates  through  the 
inserted  cions,  which  get  larger  from 
year  to  year,  the  effect  of  the  loss 
of  bark  by  girdling  is  at  least  par- 
tially remedied. 

137.  Grafting  materials. — In 
grafting  it  is  necessary  to  protect 
the  injured  tissues  by  some  coating  or  wrapping  which 
will  prevent  drying  out  and  keep  out  organisms  which 
cause  decay.  In  early  days  (and  to  some  extent  at  the 
present  time  in  Europe)  mixtures  of  clay  and  cow  manure 
were  applied  to  grafts.  Grafting-wax,  however,  has  for  a 


FIG.  60.— Bridge- 
graft  showing  ci- 
ons inserted. 


ASEXUAL  PROPAGATION  ON  ROOTS  OF  OTHER  PLANTS  83 

long  period  been  thfc  standard  material  for  this  purpose. 
Most  grafting-waxes  consist  of  three  materials;  resin  which 
gives  hardness,  beeswax  which  supplies  toughness,  and  tallow 
which  renders  the  mixture  soft  enough  to  be  worked  up.  The 
most  common  grafting-wax  is  made  of  four  pounds  of  resin, 
two  pounds  of  beeswax,  and  one  pound  of  tallow.1  The 
mixture  may  be  varied  to  suit  the  need.  In  making  the  wax, 
the  resin  is  crushed  and  melted  slowly.  Then  the  proper 
amounts  of  beeswax  and  tallow  are  added.  The  mixture  is 
kept  hot,  but  not  boiling,  stirred  vigorously  for  some  time, 
is  finally  dropped  into  cold  water,  and  pulled  like  molasses 
candy  with  hands  slightly  greased.  The  wax  can  be  applied 
to  the  grafts  by  being  warmed  and  put  on  with  a  brush,  or 
if  of  the  proper  consistency  for  the  purpose,  it  may  be  put 
on  cold  with  the  hands. 

Grafting-cloth  is  made  by  drawing  strips  of  cloth  through 
melted  grafting-wax.  Grafting-string  is  prepared  by  soak- 
ing balls  of  string  in  hot  grafting-wax. 

In  order  to  reduce  the  high  cost  of  grafting-wax  due  to  the 
expensiveness  of  beeswax,  a  number  of  substitutes  have  been 
tried.  Asphaltum  and  paraffin  mixtures  have  been  used 
successfully. 

EXERCISES 

EXERCISE  I. — Preparing  grafting-wax. 

Materials. — Resin;  beeswax;  tallow;  small  pail  or  tin  can;  twine; 
strips  of  old  cloth. 

Procedure. — Prepare  grafting-wax,  grafting-cloth,  and  grafting-twine 
in  accordance  with  the  directions  given  in  Chapter  V.  (It  is  suggested 
that  each  student  prepare  his  own  wax,  using  a  small  quantity  of  each 
ingredient  in  the  proper  proportion.) 

EXERCISE  II. — Budding. 

1.     Budding  in  the  laboratory. 

Materials. — Small  branches  of  willow;  sharp  knife;  string  for  tying. 

Procedure. — Willow  twigs  may  be  prepared  for  very  early  spring 

» For  other  formulas,  see  pages  169  to  171  of  Bailey's  Nursery-Manual. 


84 


HORTICULTURE  FOR  SCHOOLS 


budding  in  the  laboratory  by  placing  them  in  boiling  water  for  an  hour 
or  so  and  leaving  them  in  water  over  night.  On  such  prepared  material 
practice  shield-budding  and  some  of  the  other  forms,  keeping  in  mind 
the  essential  points  necessary  for  successful  budding.  Write  an  account 
of  what  you  did  and  illustrate  with  drawings. 

2.    Budding  nursery  stock. 

Materials. — Young  nursery  trees;  string;  budding-knife. 

Procedure. — Bud  the  trees  according  to  methods  described  in  the 
text.  Keep  a  careful  record  of  the  growth  of  the  buds.  If  nursery 
stock  is  not  available,  bud  upon  willow  or  other  available  trees. 

EXERCISE  III. — Practice  in  grafting. 
1.    Bench-grafting  in  the  laboratory. 

Materials. — Grafting-knife;  one-year-old  seedling  roots  of  apple  or 
pear  (these  may  be  obtained  from  nurseries);  cions  of  last  season's 
growth  of  apple  or  pear;  waxed  yarn  for  tying. 

Procedure. — Make  whip-grafts  during  the  dormant  season  according 
to  methods  described  in  the  text,  grafting  the  cions  desired  on  the  roots. 
The  roots  may  be  cut  from  two  to  six  inches  long  and  the  cion  should 

be  long  enough  to  make  the  total 
length  of  the  graft  of  convenient 
length  for  planting  later.  Wind  the 
grafts  with  waxed  cotton  yarn. 

2.  Cleft-grafting    of    nursery 
stock. 

Materials. — Seedling  nursery 
stock;  grafting- wax;  grafting-knife. 

Procedure. — Cleft-graft  the 
stock  low  down  inserting  the  cion 
desired.  Wax  all  cut  surfaces 
thoroughly. 

3.  Top-grafting. 

Materials. — Heavy  grafting- 
knife  or  grafting-tool;  worthless 
trees;  mallet  or  heavy  club;  graft- 
ing-wax. 

Procedure. — If  some  seedling  or 
worthless  trees  four  or  more  years 
old  are  available,  top-graft  them 
to  desirable  varieties  according  to 
in  this  chapter.     (Worthless  trees  in  waste  placea 


the  stock. 
methods  described 


are  good  for  class  practice  in  top-grafting.) 


ASEXUAL  PROPAGATION  ON  ROOTS  OF  OTHER  PLANTS  85 

EXERCISE  IV. — Observation  of  budding  and  grafting  methods,  and 
of  grafted  and  budded  trees. 

1.  If  there  is  a  nursery  in  your  section,  visit  it  to  see  how  grafting 
and  budding  are  done. 

2.  Examine  some  grafted  trees  in  your  neighborhood.     Notice  the 
point  at  which  the  grafting  or  budding  was  done.    Did  a  good  or  poor 
union  result?    Do  the  stock  and  cion  appear  to  be  growing  at  the  same 
rate?    In  what  varieties  of  grafted  trees  do  you  notice  the  cion  to  be 
larger  than  the  stock  or  the  reverse?    How  do  you  account  for  the 
difference  in  growth  of  the  stock  and  cion?     (See  Fig.  61.) 


CHAPTER  VI 
VEGETABLE-GROWING 

IN  THE  growing  of  vegetables  on  a  commercial  scale,  care 
must  be  observed  to  secure  a  location  suitable  for  the  pro- 
duction of  the  particular  kind  or  kinds  desired.  However, 
closeness  to  market  must  also  be  taken  into  account,  so  that 
sometimes  the  proximity  of  a  tract  of  land  to  markets  will 
justify  the  expenditure  of  relatively  large  amounts  for  the 
upbuilding  of  the  soil  and  for  rents.  In  the  home-garden 
many  varieties  of  vegetables  are  desired,  and  the  choice  of 
soil  is  limited  to  the  best  available  on  the  home  place.  Two 
facts,  however,  aid  the  home-gardener;  first,  that  in  almost 
any  type  of  soil  some  vegetables  can  be  grown;  and  secondly, 
that  with  patience  and  with  a  small  outlay  of  capital 
small  tracts  of  soil  can  be  modified  to  almost  any  extent. 
Even  the  rigors  of  climate  can  be  guarded  against  by  the  use 
of  various  devices.  Shingles,  lamp-shades,  pieces  of  tin, 
paper  bags,  glass  panes,  hotbeds,  coldframes,  and  many  other 
articles,  may  become  useful  tools  in  the  hands  of  the  ingenious. 

No  activity  will  give  more  play  to  the  ingenuity  of  a  high- 
school  pupil  than  the  raising  of  a  properly  varied  home- 
garden.  In  many  cases,  such  enterprise  will  repay  him  hand- 
somely. At  any  rate,  the  satisfaction  to  be  derived  from  the 
presence  on  the  family  table  of  fresh  vegetables  of  worthy 
quality  is  no  inconsiderable  reward. 

138.  The  soil. — In  general,  a  rich  mellow  sandy  loam  is 
preferable  for  vegetable-growing,  and  is  especially  desirable 
for  root-crops.  A  sandy  loam  is  easily  worked,  allows  roots 
to  penetrate,  favors  good  drainage,  and  warms  up  well  in 
the  spring.  A  heavy  clay  soil  is  colder  in  the  spring  than  a 

86 


VEGETABLE-GROWING  87 

sandy  one  and  is,  therefore,  not  so  good  for  early  vegetables. 
It  puddles  (sticks  together)  when  wet  so  that  air  does  not 
enter  freely,  and  tends  to  bake  and  crack  when  drying.  On 
the  other  hand,  clay  soils  hold  moisture  in  times  of  drought 
better  than  sandy  soils.  The  addition  of  organic  matter 
greatly  improves  either  a  sandy  or  clay  soil.  Organic  matter 
may  be  added  by  plowing  under  green-crops,  or  by  applying 
manure.  If  well-rotted  stable  manure  is  worked  thoroughly 
into  the  ground  in  the  fall,  the  soil  will  be  in  good  condition 
in  the  spring.  Poultry  and  sheep  manures  are  very  rich  in 
nitrogen  and  must  be  used  in  small  quantities  only.  Their 
use  gives  a  luxuriant  growth  of  stem  and  foliage.  If  the  soil 
is  acid  in  nature,  the  addition  of  lime  will  remedy  the  defect. 

139.  Plowing. — It  is  advisable  to  plow  or  spade  deeply 
for  the  growing  of  vegetables.    Fall  plowing  is  useful  as  it 
leaves  the  ground  loose  and  exposed  to  frost  and  weather 
action,  and  brings  insects  to  the  surface  to  be  destroyed  by 
the  cold.    Soil  plowed  in  the  fall  absorbs  rains  readily.    Fall 
plowing  eliminates  the  necessity  of  working  the  soil  deeply 
in  the  spring  when  weather  conditions  may  render  clays  in 
poor  condition  for  working. 

140.  Ordering  and  growing  seed. — Some  gardeners  prefer 
to  grow  their  own  seed,  but  this  requires  considerable  care 
and  attention.     For  the  home-garden  at  least  it  is  much 
cheaper  to  buy  seeds,  although  the  growing  of  seeds  is  very 
interesting.     Many  reliable  firms  grow  seeds  for  sale.     In 
buying,  the  grower  should  make  sure  that  the  seeds  were 
produced  by  a  reliable  firm  and  that  they  are  not  old  and 
lacking  in  vitality.1 

141.  Planting. — Before  seeds  are  planted,  the  soil  should 
be  pulverized  thoroughly.    For  the  home-garden  the  hand 
rake  is  a  most  useful  implement.     Most  seed  should  be 
planted  in  parallel  rows.     The  seed-beds  may  be  raised, 
depressed,  or  on  a  level  with  the  surrounding  land,  depending 

*  Tests  for  the  viability  of  seeds  are  discussed  in  Chapter  III. 


88  HORTICULTURE  FOR  SCHOOLS 

on  the  soil,  crop,  and  method  of  watering  to  be  used.  By 
means  of  a  hoe  or  stick,  a  trench  is  made  into  which  the  seeds 
are  dropped.  Seeds  may  also  be  planted  with  a  drill,  a  very 
rapid  method.  The  depth  of  planting  is  important  (see 
paragraph  68).  Seeds  sown  in  the  spring  in  moist  soil  not 
likely  to  dry  out  quickly  are  planted  less  deeply  than  the 
same  kinds  of  seed  when  sown  later  in  the  summer.  In 
planting  small  beds  it  is  convenient  to  stand  on  a  board  while 
making  the  trench  and  sowing  and  covering  the  seed.  The 
edge  of  the  board  will  serve  also  as  a  guide  in  making  a 
straight  trench.  Where  the  rows  are  longer,  a  wire  or  cord, 
stretched  between  two  stakes,  will  help  the  gardener  to  keep 
them  straight.  Light  soils  should  be  pressed  down  firmly  over 
the  seeds  to  keep  them  moist  so  they  will  germinate  readily. 
The  thickness  for  sowing  seed  varies  with  the  variety  and 
habit  of  growth  of  the  plants.  Seeds  should  be  sown  thickly 
if  they  are  low  in  viability  or  if  the  weather  and  soil  condi- 
tions are  unfavorable. 

142.  Transplanting. — Seeds  may  be  sown  in  the  garden  or 
in  flats,  or  in  hotbeds  and  later  transplanted  out-of-doors. 
Some  plants,  including  the  cabbage,  do  best  when  trans- 
planted.   Early  kinds  are  obtained  in  this  way  as  they  may 
be  started  before  it  would  be  safe  to  grow  them  outside. 
Many  times  it  is  necessary  to  "harden  off"  the  young  plants 
by  transferring  them  to  coldframes  before  setting  them  out 
in  the  open.     The  same  effect  is  obtained  by  moving  the 
flats  out-of-doors  before  the  plants  are  transplanted  to  the 
garden. 

143.  Cultivating. — After  the  plants  are  up,  frequent  cul- 
tivation is  necessary  to  keep  down  weeds  and  to  conserve 
moisture.    When  the  garden  is  large  enough,  this  work  should 
be  done  with  the  aid  of  a  horse,  but  on  small  areas  a  hand 
cultivator  on  wheels  is  a  time-saving  device.    A  considerable 
amount  of  hand  hoeing  and  weeding  is  also  necessary  in  the 
vegetable-garden . 


Plate  III. — Upper:   Planting  a  tree,  using  a  planting-board.     Lower:   An  extension 
disk,  adapted  to  cultivation  under  branches. 


VEGETABLE-GROWING  89 

144.  Thinning. — Plants  are  thinned  to  give  more  space 
for  growth.    If  just  enough  good  viable  seed  is  planted,  no 
thinning  is  necessary;  but  it  is  advisable  to  plant  an  abun- 
dance of  seed  so  that  if  the  plants  do  not  come  up  well  or  if 
cutworms  or  frosts  kill  part  of  them,  there  will  still  be  a 
sufficient  number.    Any  surplus  may  be  thinned  out  later. 

145.  Watering. — The  soil,  if  at  all  dry,  must  be  moistened 
thoroughly  as  soon  as  the  seeds  are  sown.    Water  should  be 
applied  freely  to  transplanted  vegetables  as  soon  as  they  are 
set.    Thereafter  a  good  soaking  occasionally  is  better  than 
light  sprinkling  often.    After  light  sprinklings  the  water  soon 
evaporates,  with  harmful  rather  than  beneficial  results.    The 
watering-pot  or  hose  may  be  used  on  small  areas.    A  method 
of  watering  with  overhead  pipes  known  as  the  " Skinner  system" 
is  sometimes  used,  but  is  expensive.    Irrigation  by  furrows  is 
common.    The  raised-bed  system  (in  which  the  bed  is  above 
the  surrounding  ground)  is  frequently  employed  and  is  adapted 
to  rather  heavy  soils.    Water  is  applied  in  ditches  around 
the  bed  and  soaks  up  into  it.    The  depressed-bed  system  is 
adapted  to  rather  light  soils.    Under  this  system  the  bed  has 
a  ridge  of  soil  around  it,  and  the  water  is  carried  along  a  ditch 
in  the  ridge  on  higher  ground  and  soaks  down  into  the 
bed. 

146.  Diseases  and  insects. — Sucking  insects  (for  example, 
plant-lice)  are  killed  with  Black  Leaf  40,  a  nicotine  spray, 
or  with  other  contact  sprays.    Biting  insects  (cutworms  for 
example)  are  killed  by  poisons.    Insects  which  work  under- 
ground or  at  the  surface  like  the  cutworms,  are  especially 
difficult  to  destroy,  since  poisons  sprayed  on  the  plants  cannot 
reach  them.    Late  fall  plowing  helps  to  eliminate  such  insects 
by  bringing  the  nests  to  the  surface  of  the  ground  where  they 
are  destroyed  by  the  winter's  cold.    Cutworms  can  be  killed 
by  putting  poisoned  bran  on  the  ground  close  to  the  plant. 
The  grubs  usually  prefer  the  bran  to  the  plant.    Sometimes 
pieces  of  tin  or  even  thick  paper  may  be  placed  around  the 


90  HORTICULTURE  FOR  SCHOOLS 

plant  and  down  in  the  ground  a  short  distance  to  prevent  the 
cutworms  from  getting  to  the  stem.  Crop-rotation  should 
be  practiced  where  cutworms  are  present.1 

147.  Tools. — Before  beginning  work  in  the  garden,  the 
necessary  tools  should  be  sharpened  and  otherwise  made 
ready  for  immediate  use.  For  a  small  garden,  a  spade,  a 
rake,  a  hoe,  and  a  hand-weeder  may  be  all  that  is  necessary, 
but  for  larger  gardens  the  following  list  may  prove  suggestive : 
Wheelbarrow,  mallet,  stout  cord,  tape-line,  stakes,  tin-cans, 
hand  cultivators,  spading-fork,  dibbers  (Fig.  62)  or  trowels, 
sprinkling  cans,  hose,  sprayers,  wrenches,  files,  whetstone, 
and  grindstone  or  emery  wheel.  Proper  care  will  greatly 
prolong  the  life  of  implements.  They  should 
never  be  left  out  exposed  to  the  weather. 
Paint  should  be  applied  to  tools  when 
needed.  Tools  should  be  cleaned  of  soil  after 
each  use. 

148.     Garden   plans. — It    is  well  to  plan 
the    garden    and   secure   the    necessary  seed 
somewhat  in  advance  of  planting  time.   Plans 
should  be  drawn  to  scale,  and  should  show 
FZQ.  62.— A  each   row  of  the   particular  vegetable  to  be 
grown.    The  plan  should  indicate  the  length 
of    growing    season    of   the   different   vegetables  and  the 
time  of  planting.     Such  facts  may  be  obtained  from  seed 
catalogues. 

With  many  kinds  of  vegetables  (lettuce  is  a  good 
example),  all  the  seeds  should  not  be  sown  at  once,  but 
small  quantities  should  be  planted  from  time  to  time 
throughout  the  growing  season,  that  the  supply  of  the 
vegetable  may  be  continuous. 

149.  Classes  of  vegetables.— Vegetables  may  be  classified 
according  to  the  season  favorable  for  their  growth,  as  spring, 
summer,  or  fall  vegetables.  They  may  be  classed  as  annual, 

1  Diseases  and  insects  are  treated  more  fully  in  later  chapters. 


VEGETABLE-GROWING  91 

biennial,  and  perennial.  In  the  chapters  following  they  are 
classified  according  to  the  parts  used  for  food;  namely  those 
in  which  the  underground  parts  are  eaten,  those  in  which  the 
foliage  and  stems  are  used,  and  those  in  which  the  fruits  are 
utilized.1 

i  Exercises  on  vegetable-growing  follow  Chapter  IX. 


CHAPTER  VII 
ROOT,   TUBER,  AND  BULB  CROPS 

MOST  root,  tuber,  and  bulb  crops  grow  best  in  sandy  loam 
soils  and  in  cool  climates.  A  few,  such  as  the  sweet  potato, 
require  a  warm  growing  season. 

ROOT  AND  TUBER  CROPS 

150.  The  beet. — It  is  supposed  that  the  modern  cultivated 
varieties  of  edible  beets  were  developed  from  the  wild 
forms  known  to  the  ancients.  Varieties  are  still  found 

wild  in  the  Mediterranean  region. 
The  sea  beet,  cultivated  for  its 
leaves,  is  a  native  of  the  seacoasts 
of  England.  The  chard  (Fig.  63), 
of  which  the  leaves  only  are  used 
as  food,  originated  in  Portugal,  and 
was  introduced  into  England  as 
early  as  the  seventeenth  century. 
An  ornamental  sort,  known  as  the 
Chilean  beet,  is  said  to  have  come 
from  Chile  in  South  America. 

Edible  beets  are  cultivated  to 
some  extent  in  all  parts  of  the 
United  States  and  in  many  sections 

of  Canada.  They  require  a  cool  climate  for  the  best  develop- 
ment and  are,  therefore,  grown  extensively  in  the  North. 
Beets  grow  best  and  have  roots  of  most  perfect  shape  in 
a  rich  sandy  loam,  although  they  can  be  raised  with  some  suc- 

92 


ROOT,  TUBER,  AND  BULB  CROPS  93 

cess  on  heavier  soils .  They  respond  readily  to  any  well-balanced 
fertilizer  containing  potash,  phosphoric  acid,  and  nitrogen. 
If  manure  is  applied  to  the  soil  in  the  same  season  in  which 
the  beet  seed  is  sown,  it  should  be  well-rotted.  Beets  will 
not  grow  well  on  acid  soils  unless  the  latter  are  treated  with 
lime.  Seed  can  be  sown  early  in  the  spring.  Good  sized 
tubers  are  secured  in  six  to  eight  weeks.  A  continuous  supply 
can  be  maintained  by  planting  seed  every  few  weeks  through- 
out the  growing  season.  The  seed  of  the  edible  beet  is  really 
a  fruit  containing  several  seeds,  so  that  a  number  of  plants 
result  from  each  fruit  planted.  For  that  reason,  the  seed 
should  not  be  planted  more  closely  together  in  the  row  than 
one  to  every  inch  or  two.  The  rows  may  be  from  eighteen  to 
twenty-four  inches  apart.  After  the  beets  come  up,  they 
should  be  thinned  so  that  the  roots  do  not  touch  one  another. 
In  commercial  establishments,  all  the  thinning  is  performed 
at  one  time.  In  the  home-garden,  thinning  may  be  done  from 
time  to  time  and  the  discarded  plants  used  for  greens.  The 
plants  thinned  from  the  row  may  be  reset  in  new  beds  as  they 
are  easy  to  transplant.  The  culture  of  mangels,  sugar-beets, 
and  chard  is  practically  the  same  as  that  of  the  table  beet  just 
considered. 

151.  The  carrot. — The  history  of  the  carrot  is  not  defi- 
nitely known.    The  fact  that  the  Dutch  introduced  it  into 
England  in  Queen  Elizabeth's  time  has  led  many  to  conclude 
that  it  was  brought  to  its  present  stage  of  development  in 
Holland.    The  carrot  is  grown  over  a  wide  area  of  the  United 
States  and  Canada.    The  cultural  directions  are  the  same  as 
for  the  beet,  with  the  exception  that  the  carrot  will  do  well 
on  poor  soils.    Seed  may  be  sown  early  in  the  spring,  or  at 
any  time  throughout  the  summer,  as  carrots  will  stand  heat 
well  and  mature  in  two  or  three  months,  depending  on  the 
varieties. 

152.  Celeriac,  also  called  root-celery,  is  much  like  celery 
in  appearance,  but  it  is  the  root  of  the  celeriac,  rather  than 


94 


HORTICULTURE  FOR  SCHOOLS 


the  top,  that  is  eaten.    The  roots  may  be  boiled  for  a  table 
vegetable,  or  used  in  salads  and  soups.    Celeriac  does  best 

in  a  cool  climate  and  in  a 
rich  soil.  The  seed  is  sown  in 
flats  or  in  the  greenhouse  and 
the  young  plants  are  usually 
transplanted  once  before  they 
are  finally  set  out  in  the  field. 
Celeriac  requires  no  blanch- 
ing ;  otherwise  its  culture  is  the 
same  as  for  celery  (Fig.  64). 
153.  Chicory,  which  was 
FIG.  64.— Celeriac,  used  as  a  salad  plant  by  the 

untrimmed  root  and   .->,,.  ,  . 

root   trimmed  for  Greeks  in  early  times,  is  found 

market.  .  ...  .  '  . 

in  a  wild  state  in  continental 
Europe  and  in  England.  It  is  common  along  roadsides  in  the 
older  settled  regions  of  North  America.  It  blooms  in  autumn 
profusely.  Its  flowers  are  of  the 
brightest  blue. 

The  roasted  roots  are  employed 
as  a  substitute  for  coffee.  Chicory 
roots  (Fig.  65)  are  used  as  a  table 
vegetable  also.  The  tops  are  fre- 
quently cooked  for  greens,  and 
when  blanched  are  eaten  as  a  salad. 
To  produce  the  blanched  leaves, 
the  tops  of  the  plants  are  cut  off 
in  the  fall,  and  the  roots  are  dug 
and  replanted  and  then  covered 
with  several  inches  of  soil.  An 
abundance  of  blanched  leaves  is 
then  produced.  Seeds  of  chicory 
are  sown  early  in  the  spring  in 
much  the  same  manner  as  carrot 
seeds. 


FIG.  65. — Chic- 
ory root. 


FIG.   66.— Root 
of  horse-radish. 


ROOT,  TUBER,  AND  BULB  CROPS  95 

154.  Horse-radish. — The  root  of  this  plant,  ground  and 
placed  in  vinegar,  is  used  as  a  relish.    Horse-radish  is  propa- 
gated by  root-cuttings,  the  smaller  branching  roots  being 
removed  to  furnish  the  cuttings  at  the  time  the  larger  roots 
are  dug  for  market.    Roots  one-fourth  or  one-half  inch  in 
diameter  are  made  into  cuttings  from  four  to  six  inches  long, 
the  upper  end  of  the  cutting  being  cut  squarely  across  and 
the  lower  end  slanting  in  order  to  indicate  which  end  should 
be  upward  in  planting.    The  cuttings  are  stored  over  winter 
in  sand  kept  slightly  moist,  and  are  usually  planted  in  the 
spring.    In  planting,  the  cuttings  are  set  with  the  upper  end 
just  beneath  the  surface  of  the  soil.    A  good  loam,  rich  in 
humus,  is  best  for  horse-radish  (Fig.  66). 

155.  Jerusalem  artichoke  is  native  to  Canada  and  the 
northern  part  of  the  United  States.    Like  those  of  the  Irish 
potato,  its  tubers  can  be  used  as  a  table  vegetable  and  in 
the  making  of  soups  and  salads.    The  plant  is  a  perennial, 
propagating  itself  from  year  to  year.    It  grows  well  in  poor 
sandy  soils,  but  also  responds  to  good  soils.    It  is  propagated 
by  tuber-cuttings. 

156.  The  parsnip  is  thought  to  be  a  native  of  Europe. 
It  requires  a  long  growing  season,  and  for  that  reason  the 
seed  is  sown  in  early  spring.     Parsnip  seed  produced  the 
previous  season  should  be  sown,  as  older  seed  does  not  have 
power  to  germinate.    Germination  of  even  the  best  seed  is 
slow.    A  deep  loam  is  most  suitable  for  the  parsnip.    The 
roots  do  not  grow  well  in  the  hot  summer  months,  but  in- 
crease in  size  rapidly  during  the  cooler  autumn  weather. 
The  roots  desired  for  winter  use  may  be  dug  in  the  fall  and 
stored,  but  as  freezing  improves  rather  than  injures  them, 
they  are  commonly  left  in  the  ground  and  are  dug  early  in 
the  spring  when  the  ground  has  thawed  out.     The  cultural 
directions  for  the  parsnip  are  the  same  as  for  beets  or  carrots. 

157.  Irish  potato. — The  potato  is  a  native  of  South  Amer- 
ica.    De  Candolle  states  that  the  Spaniards  introduced  it 


96  HORTICULTURE  FOR  SCHOOLS 

into  Europe  at  the  beginning  of  the  sixteenth  century.  It 
found  its  way  from  Spain  to  Italy,  and  from  there  it  was 
carried  to  Belgium.  It  soon  became  common  in  central 
Europe.  It  is  said  that  Sir  Walter  Raleigh  took  potatoes 
from  America  to  the  British  Isles  in  1585.  Potatoes  were 
soon  grown  to  a  considerable  extent  in  Ireland,  but  were  not 
introduced  into  Scotland  until  1725.  By  1750  the  potato 
was  grown  extensively  in  nearly  all  parts  of  Europe. 

While  the  greater  part  of  the  world's  supply  is  produced  in 
Europe,  America  ranks  high  in  the  production  of  potatoes. 
The  potato  is  sixth  in  value  among  the  crops  cultivated  in 
the  United  States,  40  per  cent  of  the  crop  being  produced  in 
eleven  states:  namely,  Maine,  New  York,  New  Jersey,  Penn- 
sylvania, Maryland,  Virginia,  Ohio,  Michigan,  Wisconsin, 
Minnesota,  and  California.  Potato  culture  is  the  main  horti- 
cultural industry  of  New  Brunswick;  it  is  important  in 
British  Columbia,  and,  is  carried  on  extensively  in  the 
other  vegetable-producing  sections  of  the  Dominion  of 
Canada. 

For  planting  it  is  important  to  select  good  medium-sized 
tubers  free  from  disease.  The  tubers  produce  the  new  plants 
from  the  eyes  or  buds.  It  is  common  to  cut  the  tubers  in 
pieces  of  about  two  ounces  in  weight,  each  piece  containing 
at  least  two  eyes.  The  distal  end  of  the  potato  (the  end 
farthest  from  the  point  where  it  was  attached  to  the  parent 
plant)  contains  the  best  growing  eyes.  It  is  advisable, 
although  not  absolutely  necessary,  to  cut  the  tuber  so  that 
one  or  more  of  the  better  growing  eyes  are  on  each 
piece. 

If  potatoes  are  stored  in  a  warm  cellar,  they  will  produce 
long  sprouts  before  planting  time  has  arrived.  This  should 
be  avoided  by  storage  at  a  low  temperature,  since  the  removal 
of  the  sprouts  lessens  the  vitality  of  the  tuber.  On  the  other 
hand,  it  is  desirable  to  place  the  potatoes  in  a  warm  room  for 
a  few  days  before  planting,  since  this  will  start  the  eyes  into 


ROOT,  TUBER,  AND  BULB  CROPS  97 

growth  and  save  time  after  the  potato  is  in  the  ground. 
Another  means  of  obtaining  an  early  and  rapid  growth  is  by 
placing  the  tuber-cuttings  in  moist  sand  in  a  warm  place 
until  the  tops  are  two  or  three  inches  high,  when  the  plants 
are  set  out  in  the  field.  Such  plants  grow  very  rapidly  during 
the  first  weeks  and  are  much  ahead  of  those  resulting  from 
tubers  set  in  the  ordinary  way.  In  the  northern  states,  the 
depth  of  planting  should  be  about  four  inches.  In  the  South, 
it  should  be  greater,  especially  in  light  sandy  soil. 

Potatoes  require  a  plentiful  and  even  supply  of  moisture. 
Should  the  ground  become  dry  when  the  plants  are  partly 
grown,  the  growth  will  be  halted,  and  if  it  is  started  again 
by  renewal  of  the  water  supply,  gnarled  and  uneven  tubers 
will  result.  This  is  one  reason  why  the  potato  is  planted 
deep.  Cultivation  to  retain  the  moisture  should  be  frequent. 
Irrigation  is  practiced  in  many  of  the  dry  sections  of  the 
country. 

Potatoes  require  an  abundance  of  plant-food.  This  may 
be  supplied  by  plowing  under  a  cover-crop,  or  by  the  appli- 
cation of  manure,  but  the  material  should  be  thoroughly  de- 
cayed before  the  potatoes  are  planted,  since  otherwise  scab 
and  similar  diseases  are  likely  to  result.  For  this  reason  as 
well  as  others,  it  is  advisable  to  rotate  crops  on  potato  land, 
the  manure  being  applied  to  one  of  the  other  crops.  If  a 
commercial  fertilizer  is  used,  it  should  contain  in  most  cases 
the  three  elements,  nitrogen,  phosphorus,  and  potassium. 
Frequently  potassium  is  the  element  most  needed. 

Potatoes  are  dug  by  hand  with  a  fork,  or  by  a  machine 
known  as  a  potato-digger.  They  are  then  picked  up  and 
stored  in  cool  dark  cellars,  or  buried  in  pits  at  a  depth 
sufficient  to  prevent  freezing.  Potatoes  should  not  be  allowed 
to  stand  in  the  light  for  any  length  of  time. 

The  most  common  diseases  of  the  potato  are  blight  and 
scab.  Blight  may  be  controlled  by  spraying  with  bordeaux 
mixture  at  intervals  during  the  growing  season.  Scab  is  kept 


98  HORTICULTURE  FOR  SCHOOLS 

down  by  selecting  smooth,  clean,  seed  potatoes  and  soaking 
them  a  short  time  in  a  solution  of  formalin  or  corrosive 
sublimate. 

The  Colorado  potato  beetle  is  the  most  troublesome  insect. 
It  is  controlled  by  spraying  the  plant  with  paris  green  or  with 
other  arsenical  sprays.  It  is  easy  to  kill  the  young  larvae 
soon  after  they  hatch  and  begin  feeding,  but  it  is  difficult  to 
poison  the  old  beetles. 

158.  The  sweet  potato  constitutes  an  important  crop  in 
the  southern  states  where  the  warm  days  and  nights  are 
especially  suited  to  its  growth.    The  plants  are  propagated 
in  hotbeds  and  transplanted  to  the  field.     The  thickened 
roots,  commonly  miscalled  tubers,  are  placed  just  far  enough 
apart  in  the  hotbed  to  prevent  their  touching  each  other, 
and  are  covered  with  a  few  inches  of  sand.    A  large  number  of 
slips  are  produced  by  each  potato.    These  slips  are  pulled  up 
from  the  bed,  while  the  parent  potato  remains  in  place  to 
produce  more  slips.    The  slips  are  set  out  in  the  field,  usually 
in  ground  that  has  been  ridged. 

Light  sandy  soils  produce  the  best  sweet  potatoes.  Good 
drainage  is  important.  Moisture  during  the  growing  season 
is  desirable,  but  too  much  moisture  should  be  avoided  when 
the  roots  are  maturing.  Frequently  shallow  cultivation 
should  be  given,  and  considerable  hand  hoeing  is  necessary. 

The  sweet  potatoes  are  usually  harvested  by  being  loosened 
by  means  of  a  special  plow  and  then  pulled  up  and  sorted  by 
hand.  They  require  different  storage  conditions  than  do 
Irish  potatoes,  a  warm  dry  place  being  most  suitable. 

159.  Radish. — It  is  probable  that  the  original  home  of  the 
radish  was  in  western  Asia  and  southern  Europe.    It  was  well 
known  to  the  ancients.    Radishes  are  mentioned  in  old  Chi- 
nese books  as  early  as  1100  B.  C.    Pliny  gives  interesting 
accounts  of  radishes  grown  in  Rome.    Several  varieties  were 
cultivated  in  England  in  Queen  Elizabeth's  time.    Since  then 
many  varieties  have  been  produced. 


ROOT,  TUBER,  AND  BULB  CROPS  99 

Light  fertile  soils  are  best  for  the  radish.  The  seed  is  sown 
in  rows.  The  small-growing  varieties  may  be  put  rather  close 
together  in  the  row,  but  they  should  be  thinned  to  give  the 
plants  enough  space.  In  the  home-garden,  the  radishes  may 
be  planted  closely  and  thinned  frequently,  the  roots  removed 
in  thinning  being  used  on  the  table.  Some  of  the  small  rapid- 
growing  sorts  mature  from  seed  very  quickly  (in  two  or  three 
weeks).  Radishes  must  have  plenty  of  moisture,  as  dry 
weather  checks  their  growth,  and  pithy  roots  are  the  result. 
There  are  early  sorts  of  radishes  to  be  planted  at  the  beginning 
of  spring;  summer  varieties  to  be  planted  later;  and  still 
other  kinds  suited  to  producing  fall  crops.  By  planting  the 
proper  varieties  at  intervals,  a  continuous  crop  may  be 
obtained  for  the  table. 

160.  Turnips  and  rutabaga. — Although  turnips  will  grow 
on  almost  any  type  of  land,  light  soils  produce  those  of  best 
flavor.    Seeds  of  the  early  sorts  are  sown  as  soon  as  spring 
opens.    The  later  kinds  are  planted  in  the  summer,  maturing 
late  in  the  fall,  and  are  usually  stored  for  winter  use.    The 
rutabaga  requires  a  longer  growing  season  than  does  the 
turnip.    Both  the  turnip  and  rutabaga  are  cold  climate  plants 
and  do  well  in  the  North.    In  climates  having  hot  days  and 
nights  during  the  summer,  these  crops  do  not  thrive,  and  the 
roots  become  stringy  and  bitter. 

BULB  CROPS 

The  edible  bulb  crops  include  a  number  of  plants  belonging 
to  the  onion  family,  such  as  onions,  chives,  leeks,  shallots, 
and  garlic. 

161.  Onion  (Figs.  67,  68).— The  origin  of  the  onion,  as  is 
the  case  with  many  other  plants  cultivated  from  an  early 
period,  is  somewhat  obscure.     The  onion  is  mentioned  in 
biblical  literature,  and  is  referred  to  in  the  inscriptions  ap- 
pearing upon  the  Egyptian  pyramids.    It  is  believed  to  be  a 


100 


HORTICULTURE  FOR  SCHOOLS 


native  of  Asia.     There  are  now  many  varieties  of  onions, 
differing  in  size,  shape,  color,  and  keeping  qualities. 
Like  most  bulbs,  onions  grow  best  in  cool  climates.    They 
require  an  abundance  of  moisture,  except  at 
the  time  of  ripening  when  dry  weather  is 
favorable.    The  largest  onion-producing  sec- 
tions of  the  United  States  are  in  Massachusetts, 
New  York,  Ohio,  Indiana,  Illinois,  and  Calif  or- 
//  nia.  The  onion  is  grown  as  a  commercial  crop 

to  some  extent  in  Canada. 

A  very  rich  soil  containing  an  abundance 
of  humus  is  necessary  for  the  successful  grow- 
FIG.  67.— onion  in  ing  of  onions.  A  good  loam  is  to  be  preferred, 
although  some  varieties  of  onions  grow 
well  on  muck  lands.  The  addition  of  fresh  manure  should 
be  avoided  on  account  of  the  danger  from  the  onion-maggot,  a 
very  troublesome  pest.  Well-rotted  manure  applied  the  pre- 
vious fall  is  excellent.  Onion  land  should  be  in  cultivated 
crops  two  or  three  years  before  onions  are 
planted  in  order  that  it  may  be  as  free  as 
possible  from  weeds.  It  is  very  important 
that  the  seed-bed  be  finely  pulverized.  The 
seeds  are  sown  in  rows,  about  three  seeds 
to  the  inch,  and  covered  with  about  one- 
half  inch  of  soil.  The  onion  bed  must 
be  cultivated  often  and  all  weeds  kept 
down.  The  plants  should  be  thinned 
very  early,  and  enough  space  left  between 
them  to  prevent  the  bulbs  from  touching 
each  other  when  full-grown.  In  the  nor- 
mal ripening  process,  the  onions  dry  and 
shrivel  at  the  neck  first,  and  the  leaves 
dry  later.  The  onions  are  pulled  and 
topped  and  then  stored  in  a  cool  dry  well- ventilated  place. 
Although  the  cheapest  way  to  multiply  onions  is  from  seeds, 


FIG.  68. — Top  onion, 
one  kind  of  "sets". 


ROOT,  TUBER,  AND  BULB  CROP X  101 

they  are  also  propagated  from  sets,  of  which  there  are  three 
kinds.  Some  varieties  produce  small  bulbs  on  the  top  of  the 
stalks  (Fig.  68).  In  other  varieties,  small  bulbs  form  from 
the  division  of  the  onion  in  the  ground.  These  small  bulbs 
may  be  planted  the  following  season.  This  race  is  usually 
spoken  of  as  the  potato-onion  or  multiplier.  The  third  and 
most  common  kind  of  "sets"  used  in  propagating  onions  is 
produced  by  sowing  onion  seed  very  thickly.  The  resulting 
plants  are  so  crowded  that  the  bulbs  remain  very  small. 
After  they  ripen  in  the  fall,  they  are  taken  up  and  stored  in 
the  same  way  as  bulbs  of  normal  size.  These  small  bulbs  are 
planted  in  the  spring  and  produce  a  very  early  crop  of  green 
onions.  If  left  until  fall,  they  are  harvested  as  ripe  onions. 
Another  method  of  producing  early  onions  consists  in  sowing 
seed  under  glass,  and  transplanting  the  young  plants  to  the 
field. 

The  onion  is  not  troubled  with  many  pests.  The  onion- 
maggot  is  its  worst  foe.  Rotation  of  crops  is  the  best  means 
of  combating  this  enemy.  The  onion-thrips  is  troublesome 
in  some  sections.  Spraying  with  kerosene  emulsion  is  usually 
successful.  The  most  troublesome  disease  is  onion-smut.  The 
best  remedy  is  rotation  of  crops,  but  it  is  difficult  to  get  rid  of 
the  disease.  Soaking  the  seed  for  twenty  minutes  in  a  solu- 
tion of  one  ounce  of  formalin  to  a  gallon  of  water  will  prevent 
smut  from  being  introduced  from  the  seed.  The  seed  should 
be  dried  before  being  planted. 

162.  Chives  are  perennial,  growing  year  after  year  when 
once  established.     They  are  propagated  in  the  spring  by 
division  (Fig.  69). 

163.  Garlic. — The  bulbs  of  this  plant  are  made  up  of  a 
number  of  divisions  known  as  cloves.    Garlic  is  propagated 
by  planting  these  cloves  in  early  springtime.    Garlic  has  an 
exceedingly  strong  flavor.    It  is  not  popular  in  this  country 
except  among  foreigners,  and  is  used  in  small  quantities  for 
flavoring. 


HORTICULTURE  FOR  SCHOOLS 


164.  The  leek  is  mild  in  flavor.  It  is  used  principally 
for  flavoring  soups.  Leeks  are  generally  grown  from  seeds 
planted  early  in  the  spring.  In  the  fall  the  plants  are 
blanched  by  being  banked  with  soil.  The  plants  are  usually 

left  in  the  ground 

until  very  late  in 

the  fall  (Fig.  70). 
165.  The  shallot 

produces  a  num- 
ber  of   elongated 

bulbs,  joined   to- 
gether at  the  base. 

It   is   propagated 

by  separating  and 

planting     these 

bulbs  in  the  early 

spring.   The  bulbs 

ripen  in  the  fall 
and  may  be  stored  in  the  same  way  as  onions.  In  the 
southern  states,  shallots  are  frequently  planted  in  the  fall 
and  are  sold  green  in  the  winter  when  green  onions  are  not  in 
the  market.  The  true  shallot  is  apparently  seldom  grown, 
the  plants  known  under  that  name  being  multiplier  onions; 


FIG.  69. — Chives. 


FIG.  70. — Leek. 


CHAPTER  VIII 


CROPS  GROWN  FOR  FOLIAGE  AND  STEMS 

CROPS  grown  for  stems  and  foliage  include  members  of  the 
cabbage  family,  a  number  of  plants  used  for  greens,  and 
several  eaten  as  salads. 

166.  The  cabbage. — The  scrawny  wild  cabbage  growing 
near  the  seacoast  in  England  is  probably  the  ancestor  of  the 
present-day  sorts 
(Fig.  71).  Improved 
varieties  of  cabbage  were 
cultivated  over  2000 
years  ago.  The  red 
cabbage  has  been  grown 
extensively  in  Holland 
for  hundreds  of  years, 
but  never  became  popu- 
lar in  North  America. 
The  Savoy  varies  from 
the  common  cabbage  in 
having  wrinkled  leaves 
(Fig.  72).  As  it  is  crisp,  tender,  and  of  a  delicate  flavor,  it  is 
one  of  the  best  cabbages  for  culinary  purposes. 

Cabbages  are  grown  to  a  certain  extent  in  nearly  every 
part  of  North  America,  but  the  cool  Great  Lakes  region  of 
the  United  States  and  Canada  leads  in  acreage.  A  deep  well- 
drained,  well-manured,  rich  loam  is  best  for  their  growth. 
Clay  subsoils  near  the  surface  are  undesirable. 

For  early  cabbages  the  plants  are  grown  from  seed  sown 
under  glass.  The  seedlings  are  hardened  by  being  exposed  to 

103 


FIG.  71.— Wild  cabbage  plant  in  seed  on  chalk 
cliffs  of  England. 


104  HORTICULTURE  FOR  SCHOOLS 

the  weather  for  a  few  days  during  the  daytime  after  which 
they  are  set  out  in  the  open.  For  late  cabbages,  the  seed  is 
sown  in  beds  prepared  in  the  open,  and  the  young  plants  are 

transplanted  in  the  same 
way  as  are  early  cabbages. 
Late  cabbages  make  much 
of  their  growth  in  the  fall, 
while  early  cabbages  grow 
in  the  spring  and  early 
summer. 

The  cabbage-worm  is  the 
pest  most  likely  to  cause 
trouble.  It  may  be  killed  by 

FIG.  72.— The  Savoy  cabbage.  .  , 

spraying  with  arsenate  of 

lead  or  with  paris  green,  but  these  poisons  should  not  be 
used  on  the  matured  heads  soon  to  be  eaten.  For  this 
reason,  hellebore  is  the  substance  employed  after  the  heads 
of  the  cabbages  have  formed.  It  may  be  applied  as  a  powder 
or  mixed  with  water  and  used  as  a  spray.  The  most  com- 
mon disease  of  cabbage  is  club-root.  Rotation  of  crops  is 
the  best  treatment. 

167.  Brussels  sprouts  probably  originated  in  Belgium, 
and  derived  its  name  from  the  fact  that  it  had  been  exten- 
sively cultivated  near  the  city  of  Brussels.  When  the  plant 
is  young  it  resembles  the  ordinary  cabbage,  but  as  it  gets 
older  the  stem  elongates  and  bears  buds,  one  or  two  inches 
in  diameter,  in  the  axils  of  the  leaves.  The  buds  are  the  parts 
eaten.  On  account  of  this  method  of  bearing  the  buds,  the 
plant  is  sometimes  called  the  "  bud-bearing "  cabbage,  al- 
though the  heads  of  the  common  cabbages  are  also  enlarged 
buds. 

Brussels  sprouts  can  be  grown  commercially  only  in  cool 
climates.  The  same  soil  and  culture  is  necessary  as  for  the 
cabbage.  The  size  of  the  buds  is  increased  by  cutting  off  the 
lower  leaves  along  the  stalk,  allowing  the  leaves  at  the  top 


CROPS  GROWN  FOR  FOLIAGE  AND  STEMS 


105 


FIG.  73. — Brussels  sprouts. 


to  remain  (Fig.  73).  The  sprouts  are  said  to  be  improved  by 
freezing.  Of  all  the  plants  belonging  to  the  cabbage  family, 
Brussels  sprouts  has  the  most 
delicate  flavor. 

168.  Cpllards   and   kales.— 
These  plants  do  not  form  heads 
as  do  cabbages.    The  leaves  are 
the  parts  eaten.      As   collards 
and  kales  stand  heat  quite  well, 
they  are   grown  for  the  most 
part  in  the  South  where  cab- 
bages do  not  thrive.    Their  cul- 
ture is  the  same  as  for  cabbages. 
(Fig.  74). 

169.  Cauliflower. — Italy  is  perhaps   the   original    home 

of  the  cauliflower,  or  at  least 
of  branching  broccoli  which  is 
related  to  it.  In  1600  it  was 
grown  in  England  to  a  slight 
extent,  but  by  1700  it  was  pro- 
duced extensively  for  market. 
Both  the  English  and  the 
Dutch  have  improved  the 
plant  remarkably. 
The  cauliflower  forms  a  head  consisting  of  flowers  and 

flower-stems  (Fig.  75),  differing  in  that 

respect  from  the  cabbage  in  which  the 

head  is  a  single  leaf -bud.    The  cauli- 
flower is  propagated  and  cultivated  in 

much  the  same  way  as  the  cabbage,  but 

special  attention  is  given  the  hardening 

of  the   young   plants  before  they  are 

transplanted.     The  cauliflower  is  more 

exacting  than  the  cabbage  as  to  climate. 


FIG.  74.— Kale. 


FIG.  75.— Head  of  cau- 
liflower. 


It  thrives  in  cool 


climates  near  bodies  of  water.      Cool  nights  are  necessary. 


106  HORTICULTURE  FOR  SCHOOLS 

It  can  be  grown  successfully  as  a  winter  crop  in  the  South. 
When  the  head  begins  to  form,  the  leaves  of  the  plant  are 
brought  together  around  the  head  and  tied  to  protect  the 
flowers  from  sunburn  and  to  keep  the  head  light  in  color. 
When  the  heads  are  fully  formed,  they  remain  in  best 
condition  only  a  few  days,  and  must  be  harvested  promptly. 

170.  Spinach. — Among  plants  used  for  greens,  spinach 
easily  takes  the  lead.    Spinach  requires  cool  weather,  a  rich 
soil  and  plenty  of  water.    In  the  South  it  may  be  planted  in 
the  fall  and  grown  as  a  winter  crop,  but  in  the  North  it  is 
usually  planted  in  the  spring.    It  may  be  harvested  as  soon 
as  the  leaves  attain  sufficient  size  for  handling. 

171.  Other  plants  used  for  greens  are  sea-kale,  beets, 
chard,  dandelion,  and  mustard.    Some  of  these  grow  wild  in 
profusion,  but  they  are  much  larger  when  cultivated. 

172.  Celery  is  one  of  the  leading  salad  plants.    It  prob- 
ably originated  in  England.    It  is  cultivated  to  a  great  extent 
in  Europe  and  America.    A  large  amount  of  celery  is  produced 
in  the  states  of  New  York,  Massachusetts,  Pennsylvania, 
Michigan,  Ohio,  California,  and  Florida,  and  in  the  provinces 
of  Ontario  and  British  Columbia  in  Canada. 

Celery  requires  a  cool  climate,  an  abundance  of  water,  and 
a  soil  rich  in  organic  matter.  It  grows  very  successfully  in 
muck  soil.  Celery  seeds  are  usually  sown  in  flats,  and  covered 
very  lightly  with  soil.  A  few  days  after  the  seedlings  appear, 
they  are  removed  to  other  flats  in  order  to  give  each  plant 
more  space.  In  about  three  months,  they  are  transplanted 
from  the  flats  into  the  field.  Early  celery  is  set  out  in  the 
spring.  For  a  late  crop,  celery  is  planted  in  summer.  In 
any  case,  the  celery  must  be  blanched.  With  the  early  crop 
this  is  usually  accomplished  by  means  of  boards  placed  on 
both  sides  of  the  row  to  shade  the  plants.  The  late  crop  is 
blanched  by  piling  up  soil  around  the  plant,  leaving  only  the 
top  leaves  exposed  (Fig.  76).  Another  system  of  blanching 
celery  consists  in  setting  it  so  closely  that  the  tops  shade 


CROPS  GROWN  FOR  FOLIAGE  AND  STEMS 


107 


FIG.  76. — Celery  banked  with  earth. 


one  another.     This  is  practiced  only  in  exceedingly  rich 
ground. 

173.  Cress  is  sometimes  called  pepper-grass  on  account 
of  its  pungency.    Cress  is  ^ 
easy  to  grow.  The  seed  is 

sown  in  the  open  ground, 
and  the  plant  is  ready  for 
use  in  about  six  weeks. 
It  runs  to  seed  rapidly  in 
hot  weather.  For  a  con- 
tinuous supply,  the  seed 
can  be  sown  every  two 
weeks .  Cress  needs  a  plen- 
tiful supply  of  moisture. 

174.  Endive  (Fig.  77). 
— This    salad     plant     is 

grown  from  seed  planted  in  June  or  July.    It  must  be  blanched 
since  otherwise  the  leaves  are  tough  and  bitter.  The  blanching 

is  done  by  drawing  the  leaves 
together  and  tying  them  at  the 
top.  Endive  should  be  used  soon 
after  blanching  as  the  inner  leaves 
rot  if  left  too  long. 

175.  Lettuce.— This  widely 
grown  salad  plant  thrives  on  many 
types  of  soils.  Cool  weather 
and  plenty  of  moisture  are 
favorable  for  its  growth,  although 
much  depends  on  the  selection  of 
varieties. 

There  are  several  types  of 
lettuce;  namely,  leaf  (Fig.  78), 
head  (Fig.  79),  and  cos.  Leaf  lettuce  is  the  most  easily  grown. 
The  seed  may  be  planted  in  the  greenhouse,  or  under  glass, 
or  may  be  sown  out-of-doors.  The  lettuce  is  ready  for  use 


Fia.  77. — Endive. 


108 


HORTICULTURE  FOR  SCHOOLS 


Fio.  78.— Leaf  type  of  lettuce. 


within  a  few  weeks.  Head  lettuce  is  considered  more  desir- 
able. It  cannot  be  grown 
well  under  glass  since  it  is 

9       ^^iTi^y^M^^        subject  to   rot.     As   head 

lettuce  takes  long  to  mature, 
the  seed  is  sown  in  flats, 
and  the  plants  are  trans- 
planted to  other  flats  or 
pots  soon  after  they  come 
through  the  ground.  They 
are  hardened  in  the  coldframe  for  a  week  or  two  before  being 
transferred  to  the  garden.  Head  lettuce  should  be  thinned. 
In  some  varieties  the 
heads  grow  to  be  a  foot 
in  diameter.  Thorough 
and  frequent  cultivation 
conserves  the  moisture. 
Cos  lettuce,  the  leaves  of 
which  do  not  form  a  com- 
pact head,  is  grown  in 
the  same  manner  as  head 
lettuce,  but  some  varieties 
require  blanching  of  the  FlG"  79.-Head  type  of  lettuce. 

inner  leaves.     This  is  accomplished  by  tying  the  leaves 
together  at  the  top. 

176.  Parsley  is  able  to  withstand  hot  dry  weather.  Some- 
times the  plants  are  started  under  glass,  but  they  are  hardy 
and  seed  may  be  sown  out-of-doors  early  in  the  spring  in  a 
carefully  prepared  seed-bed.  As  only  a  portion  of  the  plant 
is  picked  at  a  time,  a  few  individuals  will  furnish  a  continuous 
supply  for  the  average  family.  Parsley  is  frequently  trans- 
planted to  window-boxes  in  the  fall  where  it  will  supply 
foliage  all  winter. 


CHAPTER  IX 
CROPS  GROWN  FOR  FRUIT  OR  SEED  PARTS 

THREE  families  of  plants  furnish  most  of  the  vegetable  crops 
grown  for  fruit  or  seed  parts — the  legumes,  nightshade  family, 
and  cucurbits. 

177.  The  legumes. — The  pea  and  bean  are  members  of  a 
large  group  of  plants  called  legumes  which  bear  their  seed  in 
pods.    Other  examples  are  the  peanut,  locust,  clover,  alfalfa, 
lupine,  vetch,  and  acacia.    The  flowers  of  most  of  the  genera 
possess  the  peculiar  structure  so  familiar  in  the  sweet  pea. 
On  the  roots  of  legumes  are  tubercles  containing  bacteria 
which  take  the  nitrogen  from  the  air  and  fix  it  in  the  form  of 
compounds  available  for  plant  use.     On  this  account,  the 
legumes  can  be  grown  in  soil  deficient  in  nitrogen.    For  the 
same  reason,  they  are  valuable  crops  for  building  up  the  soil, 
and  should  occupy  an  important  place  in  plans  for  rotation. 
There  are  many  different  species  in  the  family,  yielding  diverse 
and  important  products,  as  forage,  hay,  dye-stuffs,  balsam, 
rubber,  and  oils;  but  the  two  garden  plants  of  most  impor- 
tance are  the  pea  and  bean. 

178.  The  bean  was  supposed  to  have  come  originally  from 
Egypt,  for  there  is  mention  of  it  in  the  early  records  of  the 
Egyptian  priests;  but  it  grows  wild  in  the  tropics  of  both  the 
Old  and  the  New  World,  and  forms  differing  from  one  another 
but  little  have  been  obtained  from  countries  widely  separated 
geographically.    Since  it  is  tropical,  it  will  endure  very  little 
frost;  and  must  be  planted  and  harvested  between  the  times 
of  spring  and  autumn  cold.    The  "  bush  "  or  dwarf  forms  have 
resulted  from  breeding  and  selection;  the  wild  kinds  are  of 
the  trailing  or  climbing  type. 

109 


110  HORTICULTURE  FOR  SCHOOLS 

The  bean  thrives  in  warm  weather,  and  will  grow  on 
almost  any  type  of  soil.  Loose  friable  soils  are  most 
favorable.  The  seeds  may  be  planted  as  soon  as  warm 
weather  begins.  After  the  plants  are  up,  frequent 
cultivation  is  necessary.  The  dwarf  kinds  need  no  support 
but  the  climbing  varieties  or  pole-beans  should  have  some 
support  for  the  vines. 

There  are  many  varieties  of  beans.  Certain  kinds  pro- 
ducing pods  free  from  fibers  are  used  as  string  beans  before 
the  seeds  mature.  The  pods  of  string  beans  are  either  green 
or  yellow,  the  yellow  ones  being  known  as  wax  beans.  Suc- 
cessive crops  of  string  beans  may  be  secured  by  planting 
every  two  weeks.  Dry  beans  are  planted  in  the  same  manner 
as  string  beans.  They  are  left  on  the  vine  until  the  pod  is 
ripe,  when  they  are  either  pulled  up  by  hand  or  harvested  by 
machinery.  Later  they  are  threshed.  The  lima-bean 
plant  produces  large  flat  beans.  It  requires  a  warm 
temperature  for  growth  and  a  better  soil  than  most  of  the 
others. 

179.  The  pea  was  known  to  the  Greeks  and  probably  also 
to  the  peoples  of  India  and  China.    Davenport  states  that  a 
small-seeded  variety  has  been  found  in  the,  ruins  of  ancient 
lake  dwellings  of  Switzerland  and  Savoy.1    It  grew  wild  in 
its  original  form  in  the  countries  bordering  the  Mediter- 
ranean, and  possibly  also  in  the  south  of  Russia.    The  present 
cultivated  pea  seems  to  be  of  comparatively  recent  develop- 
ment. 

Peas  require  cooler  weather  than  beans.  They  are,  there- 
fore, grown  earlier  in  the  spring.  They  are  used  both  green 
and  dry.  There  are  dwarf,  medium,  and  tall  sorts.  Their 
culture  is  similar  to  that  of  the  bean. 

180.  The  soybean  (Fig.  80)  and  cowpea  are  cultivated  in 
some  countries  for  human  food;    they  are  used  in  North 
America  for  stock  only,  despite  the  fact  that  they  are  fully 

»  Domesticated  Animals  and  Plants,  Davenport. 


CROPS  GROWN  FOR  FRUIT  OR  SEED  PARTS         111 

as  nutritious  as  the  closely  related  garden  forms.    In  this 

connection,  Davenport  says:   "Man  has  a  strange  aversion 

to  consuming  the  same  grain  he  feeds  his  stock,  and  he 

positively  refuses  to  eat  it  if  it  be  a  recent  importation.    The 

first  question  asked  of  a  new  food  plant 

is  this:    'Is  it  for  man  or  animal?7 

without  thinking  it  may  be  good  for 

both;  but  the  question  once  answered, 

the  future  of  the  thing  is  settled.    This 

is  why  all  efforts  to  introduce  Indian 

corn  into   Europe  to  replace  rye  as 

human  food  have  failed  in  the  past  and 

are  likely  to  continue  to  fail  in  the 

future.    Even  the  pauper  resists  what 

he  considers  to  be  putting  him  on  a 

level  with  the  animals." 

181.    The  eggplant  (Fig.  81)  belongs 

to  another  group,  known  as  solanaceous      FlG'  80--The  s°ybean- 

plants,   which   includes   also  the  pepper   and  tomato.    It 

requires    a    semi-tropical    climate,    thriving    well    in    the 

southern  part  of  the  United 
States.  It  does  not  flourish 
with  certainty  where  the 
nights  are  cool  or  the  sum- 
mers short.  When  grown  in 
the  North,  it  is  started  in 
the  greenhouse  and  repotted 
several  times  before  being 
transplanted  out-of-doors 

FIG.  81.-Ettplant.  rf^      ^      warm      seagon      ig 

well  under  way.  The  eggplant  requires  a  rich  soil. 
When  once  established,  it  can  withstand  rather  severe 
drought.  Its  worst  insect  enemy  is  the  Colorado  potato 
beetle.  Paris  green  applied  as  a  spray  is  the  common 
remedy. 


112 


HORTICULTURE  FOR  SCHOOLS 


182.    Red  peppers  (Fig.  82)  are  used  either  green  or  ripe. 

The  larger  kinds  are  preferred 
for  table  use,  while  the  smaller 
more  pungent  varieties  are  used 
for  pickling  and  flavoring.  Pep- 
pers are  hardy  and  easily  grown. 
Their  culture  is  similar  to  that 
of  the  eggplant. 

183.  The  tomato  (Fig.  83)  is 
native  to  America,  its  original 
home  being  in  Peru.  It  was  in- 
troduced into  Great  Britain  in 
the  latter  part  of  the  sixteenth 
century,  but  was  grown  at  first 

FIG.    82.-Pepper.  Qnly  ^  ^  ornamental  plant  and 

for  medicinal  purposes.     Italy   was  first  to  recognize  its 
value   as   an  edible  fruit.     Later 
France  and  England  used  it  for  food 
extensively. 

Tomatoes  are  grown  out-of-doors 
in  nearly  all  parts  of  the*  United 
States  and  Canada.  In  the  extreme 
North  where  the  summers  are  too 
short  to  insure  the  ripening  of  the 
fruit,  the  tomato  is  not  grown  com- 
mercially. Tomatoes  are  produced 
commercially  in  the  South,  in  the 
middle  states,  and  in  some  of  the 
western  states,  especially  California. 
Florida  supplies  the  winter  market. 

As  the  tomato  requires  warm 
weather  and  a  long  season,  in  the 
North  the  plants  are  first  grown 
from  seed  planted  in  hotbeds  or  in 
flats  in  the  greenhouse.  The  seedlings  are  transplanted 


FIG.    83. — Tomato   trained   on 
a  stake. 


CROPS  GROWN  FOR  FRUIT  OR  SEED  PARTS        113 

to  other  flats  and  are  later  " hardened  off"  in  coldframes 
or  in  the  open.  Finally  when  two  or  three  months  old, 
the  plants  are  transplanted  to  the  field.  In  warmer  parts 
of  the  country,  the  seeds  are  sown  in  flats  and  the  seedlings 
transferred  to  the  open  as  soon  as  they  can  be  safe  from 
frosts.  If  planted  deeply  they  resist  drought  well,  because 
of  the  number  of  roots  formed  and  the  depth  to  which  the 
lower  roots  reach. 

The  tomato  frequently  tends  to  grow  branches  and  foliage 
at  the  expense  of  the  fruit.  This  may  be  prevented  by  pinch- 
ing off  the  terminal  bud  of  the  main  stem  and  by  limiting  the 
supply  of  water.  To  secure  the  best  results,  the  plants  should 
be  grown  slowly,  but  should  not  be  checked  too  suddenly  in 
their  growth.  The  vines  are  frequently  tied  to  stakes  to  keep 
the  fruit  off  the  ground  and  prevent  decay.  Tomato  plants 
are  sometimes  pruned  to  single  stems.  Such  individuals 
yield  larger  fruit  and  mature  earlier  than  if  allowed  to  grow 
in  their  natural  manner. 

Young  tomato  plants  are  frequently  troubled  with  cut- 
worms. Paper  collars  placed  in  the  soil  prevent  the  cutworms 
from  obtaining  access  to  the  plants  at  the  surface.  Poisoned 
bran  mash  is  also  a  good  means  of  control.  The  most  trouble- 
some disease  is  the  fusarium-wilt.  The  remedy  is  rotation  of 
crops.  It  is  also  important  that  the  soil  be  changed  from  year 
to  year  in  the  flats  in  which  the  young  plants  are  grown,  as  the 
continuous  use  of  the  same  soil  is  likely  to  spread  the  disease. 

184.  Cucurbitous    crops    include    cucumbers,   gherkins, 
melons,  pumpkins,  squashes,  and  the  like.     All  require  a 
warm  climate  and  are  easily  injured  by  frost. 

185.  Cucumbers  are  used  in  the  green  state,  for  immediate 
consumption  or  for  pickling.    When  too  ripe  for  these  pur- 
poses, they  are  edible  when  cooked.    They  require  an  abun- 
dance of  moisture.    They  are  commonly  grown  from  seed, 
and  are  planted  in  hills  about  four  feet  apart,  in  rows  six  feet 
apart.    The  vines  cover  so  much  ground  that  care  should  be 


114        HORTICULTURE  FOR  SCHOOLS 

taken  not  to  plant  them  too  closely.  For  very  early  crops 
the  seeds  are  grown  under  glass  and  seedlings  transplanted 
to  the  field  as  soon  as  the  temperature  and  the  state  of  the 
soil  will  permit. 

The  striped  cucumber  beetle  is  the  worst  enemy  of  the 
vine  and  is  difficult  to  control.  Paris  green  applied  as  a  spray 
is  of  value.  Ashes,  powdered  lime,  and  powdered  tobacco 
are  recommended  as  repellents.  Lice  on  cucumbers  can  be 
controlled  by  applying  a  nicotine  spray. 

186.  Muskmelons  may  be  either  green-  or  yellow-fleshed. 
The  former  usually  have  an  excellent  flavor.    Muskmelons 
will  grow  on  many  types  of  soil,  but  it  should  be  rich  in 
plant-food.     They  are  very  susceptible  to  changes  in  the 
moisture  supply,  and  therefore,  should  be  grown  only  on 
well-drained  land. 

Muskmelons  are  grown  from  seed  usually  planted  in  hills 
in  the  field  after  the  weather  has  become  warm.  In  planting 
the  hills,  it  is  customary  to  place  some  manure  in  the  bottom 
of  the  hole  and  to  mix  it  thoroughly  with  soil.  Then  more 
soil  is  added  till  the  hole  is  filled.  The  seeds  are  planted  near 
the  surface  with  several  inches  of  earth  between  them  and 
the  manure.  A  number  of  seeds  are  planted  in  each  hill,  but 
the  seedlings  must  be  thinned  out  to  two  or  three.  The 
distance  apart  of  hills  and  rows  should  not  be  less  than  for 
cucumbers.  Frequent  cultivation  of  the  young  plants  is 
essential. 

Muskmelons  do  not  stand  transplanting  well,  but  in  the 
North,  in  order  to  secure  early  crops,  they  are  frequently 
started  in  paper  frames  or  little  wooden  boxes.  Later  the 
box,  soil,  and  plant  are  set  out  in  the  ground  intact. 

187.  Watermelons  are  usually  grown  on  light  sandy  land. 
They  need  a  warm  climate,  and  should  not  be  planted  on  the 
same  piece  of  ground  year  after  year.    In  the  North  only  the 
early  ripening  varieties  mature.    The  culture  of  watermelons 
is  similar  to  that  of  muskmelons. 


CROPS  GROWN  FOR  FRUIT  OR  SEED  PARTS    115 

188.  Pumpkins  and  squashes. — Field  pumpkins  (Fig.  84) 
are  grown  for  stock-feeding,  fre- 
quently in  the  corn  field.  Pie 
pumpkins  are  varieties  having  a 
superior  flavor.  There  are  several 
types  of  squashes,  such  as  the 
Summer,  the  Hubbard,  and  the 
Crookneck.  While  pumpkin 
and  squash  vines  will  stand  more 
frost  than  some  other  cucurbits, 

FIG.  84. — Field  pumpkin. 

they  are  easily  injured  by  low 

temperatures.      The   culture  of  pumpkins  and  squashes  is 

similar  to  that  of  other  cucurbits;  they  are  easily  grown. 

EXERCISES  FOR  CHAPTERS  VI-IX 

EXERCISE  I. — Study  of  seed  catalogues  to  observe  what  kinds  of 
information  can  be  obtained  from  them. 

Materials. — Seed  catalogues. 

Procedure. — Secure  seed  catalogues  from  a  number  of  seed  houses 
and  study  them.  Make  a  list  of  vegetables  which  could  be  grown  in 
your  home-garden.  Make  a  planting  calendar  for  these,  giving  time 
of  planting  and  time  of  harvesting  each  kind  of  vegetable.  Tabulate 
any  cultural  directions  you  can  find  for  growing  these  vegetables. 

EXERCISE  II. — The  plan  of  the  home-garden. 

Materials. — Large  sheet  of  drawing  paper;  ruler;  T-square;  tri- 
angle; drawing  board. 

Procedure. — Draw  a  plan  to  scale  for  the  home-garden  as  you  intend 
to  plant  it.  Show  the  rows  of  the  respective  vegetables,  their  lengths, 
distances  apart,  and  the  like. 

EXERCISE  III. — Careful  study  of  a  few  vegetables. 

Materials. — Plants  grown  in  the  garden. 

Procedure.— Study  in  the  home-garden  the  growth  of  a  few  plants 
from  the  time  the  seed  is  sown  until  the  plant  is  mature.  For  example, 
grow  onions  in  three  ways:  (1)  from  seed  for  the  sake  of  obtaining  ripe 
onions;  (2)  from  seed  for  the  purpose  of  obtaining  sets  for  the  next 
year's  planting;  (3)  from  sets.  Give  a  report  of  your  results  to  the  class. 


116  HORTICULTURE  FOR  SCHOOLS 

EXERCISE  IV. — Transplanting  vegetables. 

Materials. — Vegetable  seeds;  flats  of  soil  in  which  to  grow  seed; 
beds  in  which  to  set  out  plants. 

Procedure. — Grow  from  seed  a  number  of  plants  suitable  for  trans- 
planting. Transplant  some  and  care  for  them  until  they  are  mature. 
Transplant  others  two  weeks  later.  Let  some  grow  to  maturity  without 
transplanting.  Let  your  cultural  treatments  of  all  be  the  same.  Compare 
the  results  and  report  on  them  to  the  class. 

EXERCISE  V. — A  study  of  the  market  prices  of  vegetables. 

Materials. — Daily  newspapers  containing  market  reports. 

Procedure. — Let  the  class  study  the  movement  of  vegetables  in  the 
market  by  the  following  method.  Each  student  should  follow  the  price 
reported  for  some  one  vegetable  and  record  it  each  day  on  a  wall  chart 
kept  in  the  schoolroom  for  the  purpose.  As  new  vegetables  appear  in 
the  reports,  the  task  of  following  them  should  be  assigned  to  members 
of  the  class,  so  that  the  records  of  the  vegetable  market  will  be  complete. 
Newspaper  comment  on  the  reasons  for  the  condition  of  the  market 
should  be  brought  to  class  and  read.  A  new  chart  should  be  provided 
each  month  and  the  old  ones  preserved  so  that  comparisons  can  be  made. 
The  exercise  should  be  continued  for  at  least  four  months. 

EXERCISE  VI. — Projects.  Every  student  should  have  at  least  a 
small  vegetable  project.  If  he  does  not  have  a  varied  home-garden,  he 
should  decide  on  some  one  vegetable  crop  to  grow,  should  secure  all  the 
information  possible  in  regard  to  it  from  as  many  sources  as  are  at  hand; 
and  should  endeavor  to  make  a  financial  success  of  the  undertaking. 
He  should  prepare  the  soil,  plant  the  seed,  take  care  of  the  plants  to 
maturity,  and  keep  an  accurate  record  of  the  costs,  hours  of  labor, 
yields,  selling  prices,  profit  or  loss,  and  so  on.  At  the  completion  of  the 
project,  the  student  should  hand  in  a  careful  account  of  the  whole 
undertaking. 

Many  vegetable  plants  are  grown  first  in  the  greenhouse  or  hotbed, 
and  transplanted  later  to  the  field.  When  this  is  done  the  school  should, 
if  possible,  cooperate  with  the  student  by  furnishing  facilities  for 
raising  the  plants  in  large  quantities  so  that  they  may  be  available  for 
use  in  the  student's  own  garden  later.  Provision  should  be  made  for 
raising  at  least  the  following  plants  in  the  school  greenhouse  or  hotbeds: 
tomato,  sweet  potato,  cabbage,  cauliflower,  eggplant,  and  pepper. 
When  the  school  has  no  greenhouse,  students  may  well  exercise  their 
ingenuity  in  improvising  hotbeds  and  other  substitutes.  Small  boxes 
covered  by  panes  of  glass  and  set  indoors  at  night  are  useful. 


CHAPTER  X 
ORCHARD  MANAGEMENT 

THE  growing  of  fruit-trees  on  a  commercial  scale  should 
be  attempted  only  in  favorable  localities.  Many  kinds  of 
fruit  can  be  produced  in  the  home  orchard  under  adverse 
conditions  by  giving  each  kind  such  special  attention  as  could 
not  be  done  profitably  in  the  commercial  orchard. 

189.  Climate. — The  climate  of  a  region  is  the  sum  total 
of  its  weather  conditions  during  a  long  period  of  time.    Such 
factors  are  involved  as  heat,  cold,  humidity,  dryness,  winds, 
light,  and  sunshine.    A  newcomer  in  a  section  can  determine 
the  climate  only  with  difficulty,  for  from  the  fruit-grower's 
standpoint  a  history  of  climatic  conditions  for  only  one  year 
or  two  is  not  sufficient  to  tell  the  entire  story.    A  tree  is 
expected  to  thrive  and  bear  fruit  for  many  years. 

190.  Heat. — The  source  of  heat  is  the  sun.    Since  the 
atmosphere  enables  the  earth  to  hold  heat,  its  condition  is  a 
matter  of  importance  to  the  horticulturist.    A  moist  atmos- 
phere is  better  for  holding  heat  than  a  dry  one.    The  density 
also  makes  a  difference  in  the  amount  of  heat  the  earth  re- 
tains, as  is  shown  by  the  fact  that  at  high  elevations  less  heat 
is  retained  than  at  low  elevations  where  the  atmosphere  is 
more  dense. 

It  is  important  to  remember  that  each  fruit  requires  a 
definite  aggregate  of  heat  units,  during  its  growing  season. 
Fruits  differ  greatly  in  this  respect.  For  example,  the  date 
requires  a  large  aggregate  of  heat  units,  and  therefore  thrives 
only  in  the  hottest  climates.  The  apple  requires  a  very  much 
smaller  amount  and  hence  it  prospers  in  cold  climates. 

117 


118  HORTICULTURE  FOR  SCHOOLS 

191.  Cold. — Minimum  winter  temperatures  and  the  late- 
ness and  severity  of  spring  frosts  are  of  such  importance  that 
they  frequently  govern  the  selection  of  the  fruits  to  be  grown. 
Frost  control  is  possible  only  where  the  frosts  are  light  and 
of  short  duration.    Frost  in  spring  injures  the  young  growth, 
and  when  it  occurs  at  blooming  time  and  during  the  early 
setting  of  fruit,  it  may  cause  the  loss  of  the  entire  crop.    Still 
nights  are  conducive  to  frost,  for  if  there  is  no  wind  the  coldest 
air,  being  heaviest,  settles  down  to  the  ground  and  so  comes 
in  contact  with  the  vegetation.    For  the  same  reason,  frosts 
are  most  severe  on  lowlands  and  in  depressions,  and  lightest 
on  slopes. 

192.  Moisture. — A  certain  amount  of  water  is  necessary 
for  plant  growth,  and  a  large  quantity  is  required  for  the 
" sizing  up"  and  maturing  of  fruit.    Old  trees  require  much 
more  moisture  than  young  ones.    It  frequently  happens  that 
trees  when  young  will  thrive  on  the  rainfall  of  a  region,  in 
which,  when  they  become  older,  they  will  suffer  from  drought. 
Depth  and  character  of  soil  affect  the  amount  of  moisture 
necessary.    In  loose  soils  of  coarse  texture,  more  rainfall  is 
needed  than  is  the  case  with  soils  of  finer  texture,  which  are 
more  retentive  of  moisture.    In  humid  countries  it  is  impor- 
tant that  the  rainfall  occur  to  a  sufficient  extent  during  the 
growing  season.    In  semi-arid  regions  the  time  and  distribu- 
tion as  well  as  the  amount  of  the  rainfall  are  important.    For 
example,  an  amount  of  rain  which  would  be  sufficient  if  it 
fell  during  the  fruiting  season  might  be  inadequate  if  dis- 
tributed throughout  the  year.    Irrigation  makes  it  possible 
to  grow  fruit  in  very  dry  regions. 

193.  Air  moisture. — Air  is  said  to  be  saturated  when  it 
contains  all  the  moisture  it  is  capable  of  holding.    Warm  air 
can  hold  more  moisture  than  cold  air.    Air  blowing  over  large 
bodies  of  water  or  moist  regions  tends  to  collect  moisture, 
while  air  moving  over  arid  regions  loses  moisture.    Humid 
air  is  favorable  to  the  growth  of  most  plants,  but  encourages 


ORCHARD  MANAGEMENT  119 

certain  kinds  of  diseases  such  as  brown-rot  and  bitter-rot. 
Water  or  vapor  is  more  retentive  of  heat  than  is  air.  There- 
fore, when  the  air  is  dry,  it  cools  rapidly  after  sundown. 
This  is  of  great  importance  from  a  horticultural  standpoint 
for  it  affects  the  aggregate  of  heat  units  available  during  a 
given  period.  It  is  also  true  that  frost-injury  is  more  common 
in  dry  weather  than  in  wet  or  cloudy  periods. 

194.  Winds. — Differences  in  the  temperatures  of  bodies  of 
air  cause  winds.    Cold  air,  being  heavier  than  warm,  flows 
in  and  displaces  it,  causing  air  circulation.    Winds  may  be 
helpful  by  keeping  the  air  mixed  so  that  frosts  do  not  occur. 
Winds  may  be  harmful,  especially  during  winter,  because 
when  cold  they  have  a  drying  influence.    Winds  sometimes 
do  harm  by  breaking  trees,  especially  when  they  are  laden 
with  snow  and  ice,  by  blowing  fruit  from  the  trees,  and  by 
causing  light  soils  to  drift. 

195.  Sunshine  and  light. — As  explained  in  Chapter  II, 
plants  require  light  in  order  to  manufacture  food  material. 
Different  plants  require  various  intensities  of  light.    Some, 
such  as  orchard-grass,  grow  well  in  the  shade,  but  most  kinds 
require  direct  sunlight,  especially  for  the  production  of  fruit. 
Diffused  sunlight,  such  as  is  present  in  cloudy  weather,  is  not 
sufficient  for  fruit  production.    This  is  one  reason  why  trees 
come  into  bearing  quicker  and  ripen  fruit  faster  in  arid  than 
in  humid  regions.    It  is  a  matter  of  interest  that  experiments 
have  shown  red  light  to  be  the  best  for  plant  growth,  while 
violet  light  seems  to  give  the  best  blooming  conditions. 

196.  Soils. — Fruit-trees  differ  much  as  to  the  type  of  soil 
they  require,  but  in  general  the  soil  should  be  well-drained, 
deep,  and  fairly  retentive  of  moisture.  There  should  be  no  hard- 
pan  near  the  surface  for  this  prevents  the  roots  from  penetrat- 
ing the  soil,  lessens  the  feeding  area,  hinders  the  absorption 
of  rainfall,   so  that   the  surface   soil  may  become  water- 
logged, and  causes  the  trees  to  suffer  in  times  of  drought 
on  account  of  the  lack  of  a  deep  water-holding  area. 


120  HORTICULTURE  FOR  SCHOOLS 

Before  planting,  the  orchardist  should  make  sure  that  he 
has  the  type  of  soil  suitable  for  the  kinds  of  trees  he  desires 
to  grow.  Before  buying  land  it  is  well  to  obtain  the  opinions 
of  disinterested  residents  of  the  locality  and  also  of  the  state 
experiment  station  as  to  the  particular  piece  of  soil.  The 
depth  and  character  of  the  soil  can  be  ascertained  by  taking 
samples  with  a  soil-auger.  In  new  regions  the  vegetation  is 
frequently  a  reliable  index  to  the  soil  and  climate.  The  presence 
of  oaks,  especially  if  they  are  large,  indicates  a  good  soil  con- 
taining more  or  less  clay.  Pines  indicate  open,  sandy,  gravelly 
lands.  Sometimes  pines  grow  on  almost  sterile  sand,  as  in 
Florida  and  on  the  sandy  j  ack-pine  lands  of  the  North .  When 
pine  trees  appear  to  be  stunted,  the  land  is  very  poor.  Dig- 
ger pines  grow  in  the  Sierras  on  land  which  is  well  adapted  to 
fruit-growing.  Walnuts,  especially  when  of  good  size,  are 
found  on  deep,  loamy,  well-drained  soils  containing  a  satis- 
factory amount  of  moisture.  Willows  indicate  wet  soils  and 
frequently  poor  drainage.  Sorrel  (Oxalis)  thrives  in  sour 
ground.  Ceanothus  frequently  grows  on  land  suited  to  fruit- 
culture.  Its  size  and  vigor  tells  the  amount  of  jainfall.  Sage- 
brush grows  on  arid  land  requiring  irrigation  if  profitable 
crops  are  to  be  raised.  When  large  in  size,  sage-brush  indi- 
cates a  deep  soil,  but  if  small  and  scrubby  it  signifies  poor  or 
shallow  land.  Such  plants  as  grease-wood,  saltworts,  and 
samphires  show  the  presence  of  alkali  in  the  soil. 

197.  Selecting  a  location  for  the  orchard. — The  general 
location  should  be  selected  with  reference  to  the  climate,  the 
soil,  and  the  market.  While  nearness  to  market  is  an  ad- 
vantage, it  is  not  so  important  a  factor  as  it  was  years  ago 
when  shipping  facilities  were  much  poorer  than  they  are  to- 
day. After  deciding  on  the  general  location,  it  is  necessary 
to  select  the  site  for  the  orchard;  that  is,  the  particular  part 
of  the  district,  the  exact  place  in  the  locality,  or  the  exact 
spot  of  the  farm  upon  which  the  orchard  is  to  be  placed.  In 
selecting  the  site,  it  is  necessary  to  consider  the  topography 


ORCHARD  MANAGEMENT  121 

with  reference  to  elevation,  exposure,  rainfall,  and  nearness 
to  bodies  of  water. 

The  actual  elevation  above  sea-level  influences  the  tem- 
perature and  rainfall  of  a  region.  The  elevation  relative  to 
the  surrounding  country  determines  the  water  and  air  drain- 
age. Moderately  elevated  rolling  lands  are  especially  suited 
to  fruit-growing  because  the  cold  air  does  not  settle  over  the 
elevated  portions,  which  as  a  consequence  escape  the  frosts 
so  likely  to  be  present  on  the  lower  lands. 

Exposure  or  aspect  is  the  position  with  reference  to  the 
direction  toward  which  the  land  slopes;  for  example,  land 
sloping  towards  the  north  would  be  said  to  have  a  northern 
exposure.  The  best  exposure  depends  on  the  location  and 
the  particular  kind  of  fruit  to  be  grown.  In  selecting  an  ex- 
posure, the  presence  or  absence  of  large  bodies  of  water  is 
important.  Water  is  an  equalizer  of  temperature  because  it 
takes  up  and  gives  off  heat  more  slowly  than  does  the  air, 
and,  therefore,  prevents  frosts  by  warming  the  air.  It  is  also 
a  fact  that  in  the  spring  the  water  may  be  cold  enough  to  cool 
the  air  so  that  blossoming  is  retarded  until  danger  of  frost  is 
over.  To  be  effective,  the  amount  of  water  must  be  con- 
siderable. The  effect  of  a  large  expanse  is  seen  in  the  case  of 
Lake  Michigan.  Since  the  prevailing  winds  blow  across  the 
Lake  from  west  to  east,  grapes  and  peaches  can  be  grown 
commercially  on  certain  parts  of  the  land  on  the  east  side, 
while  they  cannot  be  grown  successfully  on  the  western  shore. 
As  the  Finger  Lakes  in  the  state  of  New  York  are  very  deep, 
they  are  effective  although  small  in  size. 

The  following  paragraph  from  Bailey's  Principles  of 
Fruit-Growing  (20th  and  .subsequent  editions)  includes 
some  important  facts  regarding  exposure  as  related  to  fruit 
production:  "In  locations  adjoining  bodies  of  water,  the  best 
slope  is  toward  the  water.  .  .  .  The  particular  direction  of 
the  slope  in  respect  to  the  points  of  the  compass  is  of  a  very 
secondary  importance.  There  is  often  great  choice  between 


122  HORTICULTURE  FOR  SCHOOLS 

the  two  sides  of  the  river  or  small  lake,  particularly  when  the 
slopes  are  sharp  and  high.  The  side  facing  away  from  strong 
prevailing  winds  is  usually  preferable,  particularly  if  the 
elevation  back  of  it  is  sufficient  to  act  as  a  windbreak.  In 
interior  or  frosty  regions,  the  best  slope  for  the  tender  and 
early-blooming  fruits,  as  a  rule,  is  one  that  retards  the  bloom- 
ing period,  thereby  causing  the  plant  to  remain  comparatively 
dormant  until  the  incidental  spring  frosts  are  passed.  In 
such  places,  therefore,  the  northward  and  westward  slopes 
are  commonly  most  advisable;  although,  if  these  slopes  are 
too  pronounced,  they  may  be  so  very  cold  and  backward  that 
what  is  gained  by  the  retardation  in  spring  may  be  lost  by 
the  retardation  in  fall,  and  the  fruits  may  fail  to  ripen 
properly,  or  be  caught  by  early  fall  frosts.  ...  In  regions 
in  which  there  is  much  danger  of  sunscald  on  the  trunk  and 
larger  branches,  as  in  the  midcontinental  country  and  in  hot 
arid  areas,  it  is  well  to  avoid  pronounced  southwestern  ex- 
posures if  possible.  ...  If  one  desires  to  secure  particu- 
larly early  results  and  bright  colors  of  fruits,  a  warm  and 
sunny  exposure,  to  the  southward  or  southeastward,  is  most 
advisable.  ...  It  is  sometimes  necessary  also,  to  study  the 
exposure  with  reference  to  prevailing  winds,  when  these  winds 
are  more  or  less  constant  and  strong.  The  selection  of  the 
aspect  may,  in  a  large  measure,  obviate  the  necessity  of 
establishing  elaborate  windbreaks." 

198.  Preparation  of  land  for  planting. — Before  setting  out 
an  orchard  on  land  previously  untilled,  it  is  well  to  grow  a 
cultivated  crop  for  at  least  a  year.  The  land  should  be  plowed 
deeply  before  the  trees  are  planted.    If  it  is  to  be  irrigated,  it 
should  be  leveled  carefully. 

199.  Choosing  the  trees. — It  is  important  that  the  young 
trees  be  chosen  with  great  care.    As  the  orchard  is  to  be  a 
long-time  proposition,  the  grower  cannot  afford  to  take 
chances  by  buying  from  any  but  reliable  nurserymen.    If  the 
local  nurserymen  can  be  depended  on,  it  is  well  to  buy  from 


ORCHARD  MANAGEMENT  123 

them.  The  purchaser  then  has  an  opportunity  to  see  the 
trees  before  he  orders  them.  Furthermore,  nurserymen  are 
likely  to  feel  more  responsibility  for  trees  to  be  planted  in 
their  own  locality  than  for  those  to  be  shipped  to  a  distance. 
Trees  which  are  true  to  variety  must  be  obtained.  It  is  very 
disappointing  and  expensive  to  purchase  trees  and  care  for 
them  until  they  come  into  bearing  and  then  learn  that  they 
are  of  some  other  variety  than  that  desired.  Trees  should  be 
of  the  proper  size  for  the  variety  at  the  time  of  setting  out. 
They  should  be  of  the  correct  age.  The  most  satisfactory  age 
for  most  varieties  is  one  year  from  the  bud  or  graft.  Some 
growers  prefer  trees  of  certain  varieties  to  be  two  years  old. 
In  any  case,  the  older  the  tree  the  greater  the  shock  in  trans- 
planting. The  trees  should  be  smooth  and  straight,  with  a 
good  top  and  root  system,  and  should  be  entirely  free  from 
disease  or  insect  pests.  The  laws  requiring  trees  sold  or 
shipped  to  be  inspected  by  competent  commissioners  have 
been  of  great  service  in  preventing  the  spread  of  diseases  and 
insects  by  the  sale  of  nursery  stock,  but  the  grower  should 
examine  carefully  all  the  trees  he  receives  before  they  are 
planted. 

200.  Care  of  nursery  stock. — After  the  trees  are  dug,  the 
roots  should  not  be  allowed  to  become  dry.    Care  should  be 
taken  in  shipping  and  hauling  not  to  expose  the  roots  reck- 
lessly.   It  is  seldom  that  the  grower  is  ready  to  plant  the  trees 
as  soon  as  they  arrive.    Immediately  on  receiving  the  trees, 
he  should  unpack  them  and  "heel  them  in."    A  trench  is  dug 
in  a  well-drained  shady  place,  the  roots  are  placed  in  it  with 
the  tops  lying  at  an  angle  and  the  soil  is  then  packed  around 
the  roots  and  the  lower  portion  of  the  tops.    This  not  only 
keeps  the  roots  moist,  but  prevents  the  tops  from  starting 
prematurely. 

201.  Laying  out  and  staking  the  orchard. — Whenever 
possible,  the  orchard  should  be  laid  out  in  rectangular  form. 
Stakes  are  driven  where  the  trees  are  to  be  placed,  so  that  they 


124  HORTICULTURE  FOR  SCHOOLS 

can  be  planted  at  a  proper  distance  apart  and  in  straight 
rows.1 

202.     Orchard  patterns.  —  There  are  three  main  systems  in 
•  •  e  •  •    common  use  in  setting  out 

an  orchard;  the  square, 
quincunx,  and  the  equi- 
•  ---  ^.0  •  lateral  triangular. 


In  the  square  system 


^ 
f'* 


, 

(Fig.  85)  the  trees  are 
•  planted  at  the  corners  of 
squares.  It  is  the  method 
in  most  common  use  and 

•  •  •  •  •   is  the  easiest  one  to  lay 

out.    A  disadvantage  of 
this  arrangement  is  that 

•  •  •  •  •   the  trees  do  not  have  an 

?io.  SS.-Square  system  of  orchard  planting. 


tions  for  developing  foliage  and  roots.    It  is  probable  that  the 
roots  use  all  of  the  area  ^ 

anyway,  so  the  objection 
is  not  very  important.  X  X  X.  X 

In  the  quincunx   sys-  ^  9  __  __^  9  9 

tern  (Fig.  86),  a  tree  is 

set  in  the  center  of  a          X  X  X 

square  as  well  as  at  each  ^  0  ____  ^  «  • 

corner.     The   fifth  tree, 
the  one  in  the  center,  is         *  * 

a  "filler,  "one  which  will   *  e  «  *  « 

bear  earlier  than  those 

planted  at  the  corners  of         x  *  x 

the  square,  and   which    ••••.• 

Will  be  removed    When    FIG.  ^6.—  Quincunx  system  of  orchard  planting. 
.  ,  .  ,  Dots  show  permanent  trees,  crosses,  fillers. 

the    other    trees    come 

1  For  a  complete  discussion  of  this  subject  the  student  should  see  Bailey's 
The  Principles  of  Fruit-Growing,  pages  194  to  217. 


ORCHARD  MANAGEMENT  125 

into  bearing.     Peaches  are  frequently  planted  as  fillers  in 
apple  orchards. 

In  the  equilateral  triangular  system  (Fig.  87),  the  trees  have 
an  equal  distance  for  growth  in  all  directions  and  are  able 
to  use  all  of  the  feeding  area.  This  method  is  also  known  as 
the  hexagonal,  because  the  six  trees  surrounding  one  within 
form  a  six-sided  figure  as  shown  by  the  lines  in  the  diagram. 


f>lt] 

<    '    ^ 

^  \  .x 


Fia.  87. — Hexagonal  or  equilateral  triangular  system  of  orchard  planting. 

Although  it  is  a  little  more  difficult  to  lay  out  an  orchard  by 
this  system,  the  effort  is  replaced  later  on  by  the  greater  ease 
with  which  cultivating  machinery,  wagons,  and  the  like,  can 
be  turned  in  the  orchard. 

203.  Distance  apart. — There  is  no  rule  to  follow  in  regard 
to  planting  distance,  since  much  depends  on  such  factors  as 
the  habit  of  growth  of  the  variety,  the  type  of  soil,  and  the 
amount  of  moisture  available.  Trees  of  upright  form  can  be 
planted  closer  than  those  of  spreading  habit.  Trees  on  rich 
deep  soils  should  be  placed  farther  apart  than  those  on  shal- 
low or  poor  land,  because  on  rich  soils  the  trees  grow  larger. 
Trees  should  not  be  planted  so  close  together  that  they  do 
not  have  sufficient  room  for  their  normal  development.  An 


126  HORTICULTURE   FOR  SCHOOLS 

individual  should  be  wholly  free  from  its  neighbors  so  as  to 
secure  light. 

204.  Preparing  the  trees  for  planting. — When  taken  from 
the  place  where  they  are  "heeled-in,"  the  trees  can  be  hauled 
to  the  field  in  barrels  containing  water  and  planted  at  once. 
If  they  are  not  to  be  set  immediately,  it  is  well  to  place  the 
roots  in  mud.    It  is  important  to  keep  the  roots  from  drying 
out,  otherwise  the  rootlets  do  not  form  readily. 

205.  Trimming    the   roots. — Any    broken  or  damaged 
roots  should  be  trimmed  to  remove  the  injured  part,  and 
roots  which  are  too  long  should  be  cut  back.     If  roots  are 
too  thick  or  interfere  with  each  other,  they  may  be  thinned 
out.      In  cutting  off,  a  clean  cut  from  the    underside   is 
desirable. 

206.  Planting-board. — The  use  of  the  planting-board  is 
convenient.    Plate  III  shows  a  good  one.    It  consists  of  a 
six-inch  board,  four  to  six  feet  long,  with  a  notch  at  each 
end  and  one  in  the  middle.     The  middle  notch  is  placed 
against  the  stake  where  the  tree  is  to  be,  stakes  are  driven 
in  the  notches  at  the  ends  of  the  board,  and  the  board  is 
removed.      The  middle  stake  can  then  be  taken  out  in  dig- 
ging the  hole.    When  the  tree  is  to  be  set,  the  planting-board 
is  placed  with  the  notches  at  its  ends  against  the  two  stakes, 
the  tree  is  held  in  position  at  the  center  notch,  and  the  hole  is 
filled. 

207.  Planting  the  tree. — The  hole  should  be  of  ample  size 
to  accommodate  the  root  system,  and  should  be  dug  only  a 
short  time  before  the  tree  is  to  be  planted  lest  it  dry  out  too 
much.     With  the  planting-board  in  place,  and  the  tree  in 
position  in  the  middle  notch,  the  soil  is  worked  in  around  the 
roots  with  the  hands,  while  at  the  same  time  the  tree  is  gently 
shaken  up  and  down.    Care  should  be  taken  to  get  the  soil 
well  worked  in  among  and  under  the  roots.    The  soil  should 
be  tramped  firmly  down  after  the  roots  are  covered,  and 
should  be  packed  again  after  the  hole  is  filled  up.    The  tree 


ORCHARD  MANAGEMENT  127 

should  be  set  at  the  same  depth  at  which  it  grew  in  the 
nursery.  If  planted  much  deeper,  especially  in  heavy  soils, 
it  is  likely  to  die  in  the  first  season. 

208.  Pruning  the   top. — After  the  tree  has 
been  set  out,  it  is  customary  to  cut  the  top  to 
a  whip  from  eighteen  to  twenty-four  inches  high 
(Fig.   88),  although  if  there  are  branches    so 
placed  as  to  form   a  proper  head  to  the  tree, 
they  may  be  left. 

209.  The  use  of  fertilizers. — No  stable  ma- 
nure or  fertilizer  of  any  sort  should  be  put  in  the 
hole  with  the  young  tree.     Manure  placed  in  the 
soil  at  the  time  trees  are  planted  not  only  pre- 
vents soil  particles  from  coming  in  contact  with 
the  roots,  but  causes  heating  of  the  soil  and 
injury  to  the  roots.     If  fertilizers  are  to  be  used 
at  all,  they  should  be  applied  to  the  land  the 
year  before  the  planting,  or  sometime  afterwards. 
Manure  as  a  mulch  about  the  tree  is  beneficial,   _ 

riG.  oo. — ohow- 

if  it  does  not  touch  the  trunk.    It  can  be  added      ing  tree  cut 

back  to  whip 

to  the  surface  of  the  soil  immediately  after  the      after  Pi ant- 
ing. 

tree  is  planted. 

210.  Care  of  the  trees  the  first  year. — There  must  be  an 
abundance  of  moisture  in  the  soil  for  the  growth  of  the  young 
tree.    If  the  supply  is  scanty,  water  may  be  added  artificially. 
Cultivation  is  necessary  to  keep  down  weeds  and  prevent 
surface  evaporation.    Insects  must  be  destroyed  if  present, 
and  fungous  diseases  may  require  attention. 

211.  Tillage  of  bearing  orchards. — Tillage  is  necessary  in 
the  orchard  to  increase  the  water-holding  capacity  of  the  soil, 
to  conserve  the  water  supply,  to  assist  chemical  activities, 
to  destroy  weeds,  and  to  break  up  the  breeding  places  of 
insects.    It  is  usually  advisable  to  plow  or  disk  deeply  either 
in  the  fall  or  early  in  the  spring  so  that  the  soil  can  readily 
absorb  rains.     During  the  summer  frequent  cultivation  is 


128  HORTICULTURE  FOR  SCHOOLS 

necessary  to  keep  down  weeds  and  to  maintain  a  dust  mulch, 
which  acts  as  a  blanket  in  conserving  moisture. 

212.  Cover-crops. — The  incorporation  of  organic  matter 
in  the  soil  to  better  its  physical  condition  and  to  increase 
plant-food  is  desirable  on  nearly  all  land.    Where  it  can  be 
secured,  there  is  nothing  better  than  stable  manure.    When 
it  cannot  be  obtained,  the  growing  of  cover-crops  may  take  its 
place  to  a  certain  extent,  especially  if  legumes  are  grown  to 
add  nitrogen  to  the  soil.     To  be  effective,  the  cover-crop 
should  be  plowed  under  to  add  organic  matter.    There  must 
be  an  abundance  of  moisture  in  the  soil  in  order  that  the 
cover-crop  may  not  rob  the  trees  of  their  moisture  supply.    A 
cover-crop  must  be  of  such  nature  that  it  will  grow  well 
during  the  time  when  water  is  plentiful,  either  in  the  rainy 
season  or  when  irrigation  water  can  be  obtained.    In  many 
hot  semi-arid  regions,  where  water  is  too  scarce  to  grow  cover- 
crops,  cultivation  to  conserve  the  moisture  results  in  burning 
out  of  the  humus  in  the  top  soil.    For  this  there  seems  as  yet 
to  be  no  satisfactory  solution. 

213.  Inter-cropping  consists  in  growing  a  money  crop 
between  the  trees  before  the  latter  come  into  profitable 
bearing.    Whether  or  not  the  grower  can  afford  to  crop  his 
orchard  in  this  manner  depends  on  the  fertility  of  the  land 
and  the  crops  he  can  grow.    The  inter-crop  should  not  come 
closer  to  the  trees  than  six  or  eight  feet  in  any  instance. 
Some  common  inter-crops  are  peas,  beans,  and  other  legumes, 
potatoes,  pumpkins,  squashes,  and  strawberries.    In  irrigated 
sections,  the  inter-crops  are  sometimes  over-irrigated  at  the 
expense  of  the  trees. 

214.  Fertilizers. — Before  taking  up  the  subject  of  fertil- 
izers for  orchards,  it  will  be  necessary  to  consider  fertilizers 
in  general.    It  has  been  found  by  experiments  that  the  plant- 
foods  most  likely  to  be  lacking  in  the  soil  are  nitrogen,  phos- 
phorus, and  potassium.    A  commercial  fertilizer  contains  some 
one  or  more  of  these  elements  in  the  form  of  a  compound 


ORCHARD  MANAGEMENT 


129 


available  to  the  plant.  There  are  various  nitrogenous,  phos- 
phorous, and  potassic  fertilizers.  A  complete  fertilizer  is  one 
carrying  all  of  these  three  elements,  but  the  term  does  not  in- 
dicate that  the  elements  are  present  in  any  definite  proportion. 

215.  Nitrogen  is  usually  the  first  of  the  three  elements 
to  be  exhausted  and  is,  therefore,  one  of  the  most  important 
of  the  commercial  fertilizers.    A  scarcity  of  nitrogen  is  ac- 
companied by  a  dwarfed  growth,  while  in  the  absence  of  this 
element  plants  will  not  grow  at  all.    This  has  been  proved  by 
many  unsuccessful  efforts  to  raise  crops  under  conditions 
where  it  was  not  possible  for  them  to  secure  any  nitrogen, 
though  they  could  obtain  the  other  plant-food  elements. 
Nitrogen  is  especially  important  when  the  growth  of  plants 
is  mostly  above  ground,  as  in  the  case  of 

lettuce.  When  the  growth  is  underground, 
however,  as  in  the  case  of  the  potato,  carrot, 
and  the  like,  nitrogen  must  be  used  more 
sparingly. 

216.  Sources  of  nitrogen. — The  simplest 
and  cheapest  method  of  supplying  nitrogen 
to  the  soil  is  by  the  use  of  leguminous  cover- 
crops.    (A  legume   is  a  plant  which  bears 
pods,  such  as  the  pea,  bean,  alfalfa,  clover, 
vetch.)    These   plants  have   on  their  roots 
small  galls  or  nodules  (Fig.  89),  caused  by 
bacteria.   The  bacteria  take  nitrogen  from  the 
air,  and  form    compounds   which  are  later 
transferred  to  the  roots  of  the  plants,  and  from 

them  distributed  throughout  the  plant  tissue.  FIQ  89_Nod 
When  these  legumes  are  plowed  under,  the  on  roots  of  legume, 
nitrogen  is  plowed  under  with  them,  enriching  the  soil.  Where 
water  power  is  abundant  and  electricity  is  cheap,  nitrogen 
for  use  in  fertilizers  is  obtained  from  the  air.  In  this  process 
an  electric  spark  causes  nitrogen  and  oxygen  in  the  air  to 
unite  chemically.  At  the  same  time,  water  dropping  through 


130  HORTICULTURE  FOR  SCHOOLS 

the  air  unites  with  this  new  compound  to  form  nitric  acid. 
The  nitric  acid  is  then  brought  in  contact  with  lime  and  forms 
a  compound  of  lime,  nitrogen,  and  oxygen  called  calcium 
nitrate.  This  source  of  nitrogen  is  certain  to  become  of  great 
commercial  importance  as  other  sources  fail. 

Thousands  of  tons  of  sodium  nitrate  (Chile  saltpeter)  are 
imported  to  the  United  States  yearly  from  Chile. 

Slaughter-house  by-products,  such  as  dried  blood  and 
tankage,  furnish  nitrogen  in  large  quantities.  Analysis  of 
dried  blood  shows  it  to  contain  from  12  to  14  per  cent  of 
nitrogen,  almost  as  high  a  percentage  as  in  nitrate  of  soda. 
It  differs  from  the  latter  in  being  a  little  less  rapid  in  its 
action  as  a  fertilizer,  an  advantage  in  some  cases  and  a  dis- 
advantage in  others. 

217.  Nitrogen  and  cover-crops. — The  nitrogen  in  the  soil 
becomes  available  under  ordinary  methods  of  cultivation  at 
the  rate  of  about  2  per  cent  each  year;  that  is,  if  an  acre  of 
land  to  a  depth  of  one  foot  contains  ten  thousand  pounds  of 
nitrogen,  cultivation  will  enable  plants  to  utilize  about  two 
hundred  pounds  of  it  yearly.    When  the  winter  rains  come, 
this  available  nitrogen,  being  soluble,  may  be  washed  out  of 
the  soil  and  lost.    Especially  is  this  true  in  sandy  or  gravelly 
land,   particularly  where  the  precipitation  occurs  as  rain 
rather  than  as  snow,  and  comes  in  large  quantities  at  a  time. 
Since  nitrogen  is  one  of  the  most  expensive  fertilizers,  the  loss 
of  it  in  this  way  is  a  serious  matter.    To  prevent  this  loss  in 
climates  sufficiently  mild  to  permit  it,  winter  cover-crops  are 
planted.    These  take  up  some  of  the  available  nitrogen  from 
the  soil.    In  the  spring  after  danger  of  washing  is  over,  they 
are  plowed  under  and  the  nitrates  are  then  returned  to  the 
soil  as  the  plants  decay. 

218.  Nitrification. — The    process    that    these    decaying 
plants  undergo  is  exceedingly  complicated  and  interesting. 
The  active  agents  are  bacteria,  which  work  in  groups,  each 
group  acting  on  certain  substances. 


Plate  IV. — Upper:    A  type  of  pruning  known  as  "heading  back  severely." 
Lower:  A  tree  pruned  to  laterals. 


ORCHARD  MANAGEMENT  131 

There  are  three  stages  in  the  process.  In  the  first  stage 
one  set  of  bacteria  causes  the  nitrogen  and  hydrogen  in  the 
decaying  vegetable  matter  to  unite,  forming  a  compound 
called  ammonia.  Sometimes  the  odor  of  ammonia  can  be 
detected  as  it  escapes  into  the  air  from  decaying  piles  of 
moist  leaves  or  manure.  The  ammonia  that  is  escaping  car- 
ries large  quantities  of  nitrogen  with  it,  for  ammonia  is  by 
weight  fourteen-seventeenths  nitrogen.  At  the  present  price 
of  this  element,  it  is  easy  to  see  that  escaping  ammonia 
represents  a  very  large  financial  loss. 

After  the  ammonia  is  produced,  other  bacteria  act  on  it, 
changing  it  to  nitrous  acid.  Then  the  nitrous  acid  is  acted 
on  by  still  another  set  of  bacteria,  which  change  it  into  nitric 
acid.  Nitric  acid  as  it  comes  in  contact  with  the  soil  unites 
with  various  compounds  already  there,  forming  soluble  salts 
known  as  nitrates  which  are  available  for  plant  use.  All  the 
nitrogen  which  is  "locked  up"  in  organic  matter  must  first 
go  through  this  process  before  it  can  be  used  by  the  plant. 
Therefore,  organic  fertilizers  which  carry  nitrogen,  such  as 
blood  and  tankage,  are  not  immediately  available  to  the 
plant,  but  must  stay  in  the  soil  long  enough  for  the  nitrifica- 
tion process  to  take  place.  The  nitrogen  is  then  available. 

219.  Phosphorus  is  a  yellowish  semi-transparent  sub- 
stance. Because  of  its  affinity  for  oxygen,  it  must  be  kept 
under  water  or  oil;  if  exposed  to  the  air  for  even  a  brief  time, 
it  forms  a  white  smoke-like  substance,  a  compound  composed 
of  oxygen  and  phosphorus  (phosphorus  pentoxide)  which  is 
heavier  than  air,  and  which  dissolves  in  water,  forming 
phosphoric  acid.  If  introduced  into  the  soil,  it  there  unites 
with  various  soil  substances,  forming  phosphates.  Phos- 
phates are  among  the  most  important  plant-foods  in  the  soil. 
The  phosphorus  used  in  fertilizers  is  derived  principally  from 
calcium  phosphate  and  from  ground  bone.  The  former  is  a 
mineral  occurring  especially  in  Tennessee  and  South  Carolina. 
It  is  mined,  ground  fine,  and  sold  in  this  form  as  raw  rock 


132  HORTICULTURE  FOR  SCHOOLS 

phosphate;  or  it  is  treated  with  sulfuric  acid  to  form  a  com- 
pound known  as  super-phosphate.  Raw  rock  phosphate  be- 
comes available  to  plants  very  slowly,  and  there  is  little 
appreciable  effect  from  it  until  after  a  period  of  years. 
Super-phosphate,  on  the  other  hand,  dissolves  readily,  and 
becomes  available  to  the  plant  at  once.  However,  it  is  very 
much  more  expensive  than  raw  rock  phosphate.  Ground 
bone  is  a  by-product  of  the  meat  industry.  Before  being 
ground  the  bones  are  usually  steamed  in  order  to  remove  the 
substances  used  in  the  manufacture  of  gelatine  and  glue. 
This  steaming  process  also  dissolves  out  the  fat,  thus  making 
the  final  product  very  much  more  desirable  for  fertilizing 
purposes;  for  if  the  fat  is  not  removed,  it  forms  a  thin  film 
about  each  particle  of  bone  and  so  hinders  the  process  of 
decay  in  the  soil  as  to  render  the  bone-meal  practically  use- 
less for  fertilizing  purposes  for  a  considerable  period  of  time. 
The  steaming  process  is  of  further  benefit  in  that  the  appli- 
cation of  heat  hastens  the  breaking  up  of  the  phosphate  com- 
pounds of  the  bone,  thus  making  some  of  the  phosphorus 
immediately  available  to  the  plant. 

Phosphorus  is  also  obtained  from  Thomas  slag,  a  by- 
product in  the  refining  of  iron  ore,  containing  from  15  to  20 
per  cent  of  phosphoric  acid.  It  is  ground  to  a  fine  powder 
before  being  used  as  a  fertilizing  material. 

220.  Potash. — A  considerable  portion  of  the  potash  used 
in  the  United  States  is  imported  from  foreign  countries, 
although  mineral  deposits  have  been  found  in  this  country. 
Potash  is  also  secured  as  a  by-product  in  the  manufacture  of 
cement.  The  dust  from  the  mills  is  collected  and  treated  in 
such  a  way  as  to  extract  the  potassium  compounds  from  it. 
This  not  only  yields  more  than  sufficient  potassium  sulfate  to 
pay  for  the  process,  but  also  to  a  great  extent  eliminates  the 
very  considerable  injury  formerly  done  by  the  cement  dust 
in  killing  plants  growing  in  the  vicinity. 

Soils  derived  from  a  granite  source  are  likely  to  be  rich  in 


ORCHARD  MANAGEMENT  133 

potash,  for  granite  contains  feldspar,  a  mineral  which  carries 
large  quantities  of  potassium.  As  a  rule,  therefore,  where 
soils  have  been  derived  from  a  nearby  granite  source,  they 
contain  an  abundance  of  potash,  and  it  is  not  necessary  to 
add  any  in  the  form  of  fertilizer.  On  the  other  hand,  swamp 
soils  generally  contain  an  abundance  of  organic  matter  and 
ample  nitrogen,  but  are  frequently  so  deficient  in  potassium 
that  they  are  practically  worthless  until  this  element  is 
added. 

Potassium  in  the  soil  becomes  available  very  slowly.  In 
this  it  differs  from  nitrogen.  It  has  already  been  stated  that 
about  2  per  cent  of  the  total  nitrogen  content  becomes  avail- 
able each  year.  Of  the  potassium  in  the  soil,  only  about  one- 
fourth  of  one  per  cent  becomes  available  in  any  one  year. 
Thus,  the  nitrogen  becomes  available  approximately  eight 
times  as  fast  as  the  potassium.  Phosphoric  acid  stands  as 
regards  availability  about  half  way  between  these  two. 

One  of  the  best  methods  whereby  the  amount  of  available 
potash  and  phosphoric  acid  can  be  increased  is  by  the  addi- 
tion of  organic  matter.  This  is  especially  true  in  the  regions 
of  relatively  small  rainfall,  where  humus  is  already  deficient. 
The  raising  of  cover-crops  and  the  plowing  under  of  manure 
constitute  the  most  rational  processes  of  fertilization  in  these 
parts  of  the  country. 

221.  Fertilizers  for  fruits. — In  fruit-growing  the  use  of 
fertilizers  gives  a  better  quality  of  fruit,  a  larger  yield,  and 
in  orchards  fertilized  year  after  year,  a  longer  period  of 
profitable  bearing.  But  fertilizers  must  be  applied  intelli- 
gently. The  character  of  the  soil,  the  nature  of  the  crop,  the 
prices  of  fertilizing  materials,  all  must  be  taken  into  account. 
No  specific  recommendations  can  be  made  since  each  locality, 
and  indeed  each  orchard,  is  a  separate  problem.  There  are 
a  few  general  rules  that  it  is  well  to  keep  in  mind :  (1)  Nitro- 
gen induces  wood  and  leaf  growth,  and  beyond  a  certain 
point  these  compete  with  fruit  growth.  (2)  The  most  cheaply 


134  HORTICULTURE  FOR  SCHOOLS 

available  source  of  nitrogen  is  the  atmosphere,  the  most  effi- 
cient agent  for  its  fixation  in  the  soil  being  the  bacteria  which 
live  on  the  roots  of  legumes.  (3)  Since  the  object  in  the  use  of 
fertilizers  is  to  secure  larger  net  financial  returns,  the  process 
should  never  be  carried  to  a  point  where  increased  yield  is  not 
sufficient  to  pay  increased  costs.  (4)  The  state  experiment 
stations  have  studied  the  problem  of  fertilizers  for  their  own 
localities  at  first  hand,  and  their  publications  will  give  valu- 
able assistance  to  the  orchardist. 

222.  Pruning  methods  vary  somewhat  for  different  species 
of  trees,  and  sometimes  for  varieties  within  a  species.    They 
differ  also  in  separate  regions.    It  is  not  the  purpose  of  this 
chapter  to  treat  of  all  pruning  systems,  but  of  the  principles 
which  are  generally  applicable.1 

223.  Pruning  young  trees. — As  has  been  stated,  when  the 
young  tree  is  removed  from  the  nursery,  a  considerable  loss 
of  root  results.     On  this  account,  at  transplanting  time  or 
shortly  thereafter,  the  top  must  be  reduced  to  maintain  a 
proper  balance  of  the  part  above  ground  with  the  roots.    At 
this  time  one  must  have  in  mind  also  the  establishing  of  the 
permanent  form  of  the  tree.     It  is  customary  to  cut  the 
young  tree  back  to  a  whip,  with  the  top  eighteen  to  twenty- 
four  inches  high  (Fig.  88).    However,  when  the  young  trans- 
planted tree  already  has  branches  properly  located  on  the 
trunk  to  form  the  scaffold  branches  they  may  be  left  and  all 
others  cut  off. 

In  trees  pruned  to  a  whip  after  planting,  it  is  advisable  soon 
after  growth  starts  in  the  spring  or  early  summer  to  pinch 
out  the  terminal  bud  of  all  shoots  except  the  ones  desired  for 
scaffold  branches.  The  removing  of  the  terminal  buds  in  the 
undesirable  shoots  prevents  their  growth  in  length  but  allows 
the  leaves  already  produced  to  remain  for  shading  the  trunk. 

1  For  more  complete  information,  the  student  should  read  such  publica- 
tions on  pruning  as  Kain's  Pruning  Book,  Bailey's  Pruning- Manual,  and  the 
bulletins  on  pruning  issued  by  the  state  experiment  stations. 


ORCHARD  MANAGEMENT 


135 


MAIN  BRANCH 


This  also  aids  in  forcing  out  the  buds  and  branches  desired 
for  the  framework  of  the  tree.    Usually  three  are  left  to  form 

the  main  framework.  They 
should  be  well  distributed 
LATERAL  around  the  tree  and  should 
not  be  closer  to  each  other 
than  six  or  eight  inches 
(Figs.  90-91). 

After  the  first  growing 
season,  in  the  dormant  period, 
pruning  is  done  to  give  the 
proper  shape  to  the  tree. 
The  main  branches  previously 
selected  to  form  the  frame- 
work are  allowed  to  remain, 
being  headed  back  or  cut  to 
laterals  (side  branches).  All 
other  branches  are  removed. 
In  the  second  and  third  sea- 
son, with  few  exceptions,  it  is 
only  necessary  to  thin  out  unnecessary  branches  or  at  most 
to  cut  to  laterals.  (See  Plate  IV.) 

224.  Pruning  trees  of  bearing  age. — Many  trees,  if  prop- 
erly pruned  and  in  good  soil,  begin  to  bear  fruit  as  early  as 
the  fourth  season.  Recent  investigations  have  led  to  modi- 
fications in  the  older  methods  of  pruning.  In  pruning  bearing 
trees,  it  is  advisable  to  thin  out  the  branches  to  admit  light 
and  air,  then  fruit-spurs  and  fruit-buds  usually  develop  in 
profusion.  Cutting  to  laterals  is  also  beneficial.  Continual 
heavy  heading  back  is  not  advisable,  for  it  results  in  the 
growth  of  a  large  number  of  small  shoots  near  the  cut  ends 
so  that  wood  growth  rather  than  the  development  of  fruit- 
spurs  and  buds  is  the  result,  and  the  tree  becomes  very 
"bushy,"  requiring  heavy  pruning  the  following  year.  Sun- 
burn is  likely  to  occur  after  heavy  heading.  Branches  may 


FIG.  90. — A  one-year-old  apple  tree  before 
pruning.  The  lines  show  where  to  cut. 
Three  scaffold  limbs,  a,  b,  c,  are  left. 


136 


HORTICULTURE  FOR  SCHOOLS 


well  be  headed  back,  however,  to  keep  them  within  bounds 
and  to  give  proper  shape  to  the  tree. 

225.  Summer  pruning. — Although  pruning  is  usually  done 

in  the  dormant  season,  it  is  sometimes 
practiced  during  the  growing  season  in 
summer  to  accomplish  certain  special 
purposes.  Summer  pruning  results  in  a 
shock  to  the  tree,  and  the  later  in  the 
period  of  most  active  growth  it  is  done 
the  greater  is  the  shock.  For  this  reason 
summer  pruning  is  not  generally  advisa- 
ble, although  it  is  sometimes  of  value 
in  checking  a  too  exuberant  wood 
growth.  The  main  argument  for  summer 
pruning  is  that  it  conduces  to  the  pro- 
duction of  more  highly  colored  fruit  by 
admitting  to  the  branches  more  than  the 
usual  amount  of  sunlight. 

226.  Pruning  tools. — Some  good  pruning  saws  and  shears 
are  illustrated  in  Figs.  92-97.    Pruning  tools  must  be  strong 
and    sharp.      Long-handled 

shears  should  have  a  rather 

thin  blade,  a  bar  curved  so 

as  to  hold  the  branch  firmly 

while  cutting,  and  should  be 

so  constructed  that  the  blade  has  a  slight  "draw  cut"  as 

the  handles  are  closed. 

227.  Making  the  cuts. — In  pruning  to  a  bud,  the  branch 
is  cut  off  a  short  distance  above  the  bud.    In  removing  a  side 
branch  or  a  lateral,  the  cut  should  be  made  as  close  to  the 
main  branch  as  possible.    By  selecting  a  bud  pointing  in  the 
right  direction,  branches  may  be  so  cut  that  the  growth  from 
the  bud  will  take  place  in  any  direction  desired.     In  this 
manner  it  is  possible  to  spread  close-growing  trees,  and  to 
close  up  wide-spreading  trees.    In  cutting  off  a  branch  to  a 


FIG.  91. — The  apple 
tree  in  Fig.  90  aft- 
er pruning. 


FIG.  92. — Pruning  saw. 


ORCHARD  MANAGEMENT 


137 


bud,  the  blade  of  the  pruning  shears  should  be  next  to  the 
bud,  and  the  bar  away  from  the  bud  in  order  to  avoid  injury 
to  the  part  of  the  branch  remaining.  In  the  same  way,  in  re- 
moving a  lateral  the  blade  should  be  next  to  the  branch  which 

is  to  remain,  otherwise  ragged  wounds  are  left. 

Furthermore,  if  the  hand-shears  are  not  held  in 

the  position  indicated,  they  will  soon  be  sprung 

and  become  worthless.  In  removing  side  branches, 

care  must  be  taken 

not  to  leave  stubs, 

for  these  dry  out  and 

decay,  thus  afford-  FlG'  94'~ Pruning  saw- 

ing  opportunity  for  the  entrance  of  disease.     It 
FIG.  93.— Fold-  should  be  remembered  that  cutting  off  a  portion  of 

a  branch  retards  its  growth  in  length  and  diameter. 
In  some  trees  wounds  heal  rapidly,  in  others  very  much 
more  slowly.  Wounds  are  exceedingly 
slow  to  heal  in  the 
peach,  but  heal  rapid- 
ly in  the  apple.  It  is 
advisable  to  paint  over 
all  large  wounds,  es- 
pecially in  trees  slow 
to  heal,  with  a  protec- 
tive mixture  heavy 
enough  to  hold  the 
moisture  within  the 
wound  and  prevent  dry- 
ing out  and  checking, 
and  the  consequent 
entrance  of  disease. 
White  lead  paint, 
asphaltum,  and  oronite 

.  95.-Prung      areUSed     Successfully 

shears,  for  this  purpose. 


Fia.  96.  — Pruning 
shears. 


138  HORTICULTURE  FOR  SCHOOLS 

228.  Spraying. — Spraying  is  one  of  the  most  necessary 
tasks  the  orchardist  has  to  perform.    To  be  successful  he  must 

know  what  insects  or  diseases 
he  is  spraying  for,  and  must 
apply  the  spray  at  the  proper 
time  and  so  that  no  parts  of 

FIG.  97.-Pruning  shears.  ^  ^  ^  migsed 

229.  Spraying  machinery. — Spraying  machinery  must  be 
of  such  construction  that  the  spray  can  be  applied  rapidly 
and  effectively  over  the  entire  tree.    There  are  many  types 
of  spray  machines,  such  as  hand  sprayers  for  small  plants  or 
trees,  knapsack  sprayers  for  applying  both  liquid  or  dust 
preparations,  bucket  pumps  and  power  outfits.    The  latter 
are  the  best  for  large  orchards.    A  power  outfit  consists  of  a 
tank  to  hold  the  spray,  a  pump  which  should  be  able  to  keep 
up  a  high  pressure,  an  engine  for  running  the  pump,  an  agi- 
tator for  keeping  the  spray  in  the  tank  mixed,  a  pressure 
gauge  and  regulator  for  maintaining  a  uniform  pressure  and 
a  truck  on  which  the  outfit  is  mounted.    All  parts  of  the 
outfit  should  be  durable  in  construction,  and  the  parts  which 
come  in  contact  with  the  spray  should  be  of  some  material 
which  does  not  corrode  easily;  for  valves  brass  is  best,  and 
for  the  tank  wood  is  generally  used. 

230.  Nozzles  and  spray-rods. — There  are  many  kinds  of 
nozzles,  some  suited  for  general  work  and  others  for  special 
purposes.    One  of  the  most  common  is  the  disc  type  in  which 
the  spray  is  forced  out  with  a  whirling  motion  through  a 
small  hole  in  a  disc.    There  are  many  types  of  needle-point 
nozzles,  in  which  a  needle  is  so  placed  as  to  disengage  the 
material  when  the  nozzle  clogs.     Needle-point  nozzles  are 
now  largely  replaced  with  those  of  the  disc  type.    Bordeaux 
nozzles  are  of  value  for  spraying  coarse  materials. 

A  spray-rod  consists  of  a  hollow  rod  of  some  light  material 
through  which  the  liquid  travels  from  the  hose  to  the  nozzle. 
The  rods  are  of  different  lengths,  depending  on  the  size  of 


ORCHARD  MANAGEMENT  139 

the  trees  to  be  sprayed.  A  comparatively  recent  invention, 
known  as  the  spray-gun,  is  now  rapidly  replacing  the  spray- 
rod  for  most  types  of  work.  The  spray-gun  is  a  short  rod 
equipped  with  apparatus  to  regulate  the  fineness  of  the  spray 
and  the  height  of  the  stream.  It  is  light  and  easy  to  handle 
and  permits  of  rapid  and  thorough  work. 

231.  Kinds  of  sprays. — Sprays  are  of  two  sorts;  liquid, 
and  dust  sprays,  each  of  which  has  its  advantages.  Powder 
or  dust  sprays  do  not  require  elaborate  machinery  for  their 
application,  and  can  be  used  on  fruits  just  before  they  ripen 
without  injury,  and  may  be  applied  when  the  ground  is  too 
soft  to  permit  of  the  use  of  a  heavy  liquid  spray  outfit.  On 
the  other  hand,  liquid  sprays  can  be  applied  more  evenly  and 
at  a  greater  distance  than  dust  sprays,  adhere  better,  and 
can  be  used  when  there  is  considerable  wind. 

Sprays  for  fungous  diseases  are  known  as  fungicides. 
Bordeaux  mixture  and  lime-sulfur  preparations  are  the  com- 
monest. Sprays  applied  for  the  purpose  of  combating  insects 
are  called  insecticides.  These  comprise  poisons  for  chewing 
insects,  and  contact  sprays  which  kill  the  insects  by  corrosive 
action  on  the  body  or  by  stopping  up  the  breathing  pores. 
Paris  green  and  arsenical  poisons  are  examples  of  the  former; 
kerosene  or  crude  oil  emulsions  are  examples  of  the  latter. 
Some  materials  are  used  both  as  insecticides  and  as  fungi- 
cides, as  lime-sulfur  solution.  There  is  also  the  fumigation 
process  in  which  gas  is  depended  on  for  destruction  of  pests. 
Hydrocyanic  acid  gas  and  carbon  bisulfide  are  much  em- 
ployed for  this  purpose. 

Formulas  for  making  various  spray  materials  are  well 
standardized.  The  student  can  obtain  from  the  experiment 
station  in  his  state  definite  information  in  regard  to  spray 
formulas,  making  spray  mixtures,  and  applying  sprays  for 
the  kinds  of  insects  and  diseases  common  to  the  section  of 
the  country  in  which  he  resides.  There  are  also  a  number 
of  good  books  on  the  subject. 


140  HORTICULTURE  FOR  SCHOOLS 

232.  Thinning  the  fruit. — When  fruit-trees  are  allowed  to 
bear  too  heavily,  the  fruits  do  not  reach  the  proper  size,  and 
the  value  of  the  crop  is  lessened.    Thinning  of  the  fruit  by 
hand  is  resorted  to  with  plums,  peaches,  apples,  and  the  like. 
Thinning  should  be  done  while  the  fruit  is  small,  before  it 
has  had  a  chance  to  draw  heavily  on  the  tree  for  food  and 
moisture  supply. 

233.  The  personal  factor. — The  success  of  orcharding 
depends  largely  on  the  personal  interest  of  the  owner.    If  he 
is  willing  to  give  his  individual  time  and  attention  to  the 
management  of  the  orchard,  rather  than  leave  the  matter 
to  tenants,  and  has  selected  a  suitable  locality,  his  success 
is  reasonably  certain. 

EXERCISES 

EXERCISE  I. — Laying  out  and  staking  an  orchard. 

Materials. — Stakes  sharpened  at  one  end;  surveyor's  chain,  or  wire, 
steel- tape  or  other  tape  measure;  mallet  for  -driving  stakes. 

Procedure. — Upon  a  vacant  piece  of  ground  lay  out  and  stake 
orchards  according  to  the  three  methods  mentioned  in  this  chapter. 
(Several  students  should  work  together.) 

EXERCISE  II. — Planting  trees. 

Materials. — Young  trees  for  planting;  planting-board;  stakes; 
mallet;  shovel  or  spade;  tub  of  water  in  which  to  keep  the  roots  of 
the  trees  moist  until  they  are  planted. 

Procedure. — Prune  the  roots.  Then  plant  the  trees  carefully 
following  the  essentials  for  success  mentioned  in  the  text.  After  the 
trees  are  set  out,  prune  the  tops  in  the  manner  suggested  in  the  text. 

EXERCISE  III. — Observation  of  orchards  in  the  locality. 

Procedure. — 1.  Study  different  planting  systems  in  your  locality. 
How  far  are  the  trees  apart?  Are  they  far  enough  apart?  2.  Notice 
good  and  poor  orchards  in  your  locality.  State  in  what  respects  each 
of  the  following  are  responsible  for  the  condition  of  the  orchards 
examined:  (a)  climate,  (b)  location,  (c)  soils,  (d)  care. 

EXERCISE  IV. — Pruning  studies  and  pruning  Of  bearing  trees. 
Materials. — Pruning-shears,  and  saw;   fruit-trees  for  the  student  to 
study  and  prune. 


ORCHARD  MANAGEMENT 


141 


Procedure. — Study  some  bearing  trees.  How  old  are  the  trees? 
What  kind  are  they?  What  variety?  How  can  you  distinguish  fruit- 
buds  from  leaf-buds?  How  are  the  fruit-buds  arranged  with  reference 
to  the  leaf-buds?  Are  the  fruit-buds  borne  on  spurs  or  on  laterals? 
Upon  wood  of  what  age  are  they  borne?  How  will  this  influence  your 
pruning  of  trees  this  year?  What  facts  enable  you  to  tell  by  observation 
the  amount  of  wood  growth  during  each  of  the  several  past  years? 
How  many  years'  growth  can  you  trace?  State  the  objects  to  be  attained 
in  pruning  these  particular  trees. 

2.  Prune  one  or  more  of  the  trees  studied.  Write  a  full  account  of 
your  procedure.  A  brief  description  of  the  tree  before  and  after  pruning 
should  be  included  in  your  written  exercise.  Special  difficulties  which 
you  have  encountered  may  be  mentioned.  Drawings  or  diagrams 
relative  to  the  following  should  be  included:  (1)  Drawing  showing 
typical  shape  and  relative  size  of  fruit-buds  as  compared  with  leaf -buds. 
(2)  Drawings  showing  position  and  arrangement  of  fruit-buds  upon 
branches.  (3)  Diagrams  or  photographs  showing  typical  shape  and 
condition  of  trees  before  and  after  pruning.  (4)  Diagrams  showing 
how  to  make  the  different  cuts  used  in  pruning. 

EXERCISE  V. — Study  of  spray-nozzles,  guns,  and  spraying  machinery. 

Materials. — Spray-guns;  nozzles;  power  spray  outfits;  tubs  or  pails; 
gallon  measure;  watch;  wire  screen  in  frame;  long  stick  or  hoe  handles. 

Procedure. — 1.  Study  the  construction  of  various  spray-nozzles  and 
spray-guns.  Make  diagrams  of  each  type. 

2.  Perform  the  following  tests  on  nozzles  and  spray-guns:  (1)  With 
the  pump  running  so  as  to  produce  proper  pressure,  obtain  the  normal 
discharge  a  minute  of  each  nozzle  and  gun  by  running  water  through 
the  nozzle,  collecting  the  spray  in  a  tub  or  in  pails  and  measuring  the 
amounts.  (2)  Test  the  force  of  the  spray  from  each  nozzle  and  gun  by 
measuring  the  distance  the  spray  will  reach.  (3)  Test  the  area  the  spray 
will  cover  by  measuring  the  diameter  of  the  area  covered  by  the  spray 
at  the  same  distance  from  each  nozzle.  This  may  be  ascertained  by 
directing  the  spray  on  a  fence  or  building.  (4)  Test  the  force  of  the  spray 
from  different  nozzles  by  placing  a  wire  screen  in  the  path  of  the 
spray  at  a  definite  distance  from  the  nozzles.  Notice  the  distance  the 
spray  travels  after  passing  through  the  screen.  (5)  Determine  whether 
the  spray  comes  out  of  the  nozzle  as  a  solid  cone  or  as  a  hollow  cone 
by  putting  a  stick  through  the  cone  of  spray.  (6)  Summarize  the  good 
and  bad  points  of  each  spray-gun  and  nozzle. 


CHAPTER  XI 
IRRIGATION  AND  DRAINAGE 

THE  records  of  irrigation  practice  extend  far  into  the  dim 
past  of  human  affairs.  Plato  obtained  from  his  ancestor 
Solon  an  account  of  a  mythical  island  named  Atlantis, 
situated  in  the  Atlantic  Ocean  beyond  the  Pillars  of  Hercules 
(that  is,  the  Straits  of  Gibraltar).  In  the  account  the  island 
was  described  in  great  detail,  the  part  of  the  description  of 
special  interest  being  that  of  the  irrigation  system,  which 
was  exceedingly  complete  in  every  detail.  According  to 
Plato's  story,  this  account  had  been  given  to  Solon  by  an 
Egyptian  priest  who  stated  that  the  fabled  island  in  question 
existed  10,000  years  before  his  time;  and  Solon  lived  2,500 
years  ago!' 

We  know,  also,  of  extensive  irrigation  works  among  the 
Egyptians  which  were  constructed  at  least  twenty  centuries 
before  the  Christian  era.  Indeed  in  Egypt  today  irrigation 
is  practiced  in  ways  that  epitomize  the  achievements  of 
hundreds  of  centuries,  for  land  is  watered  by  the  slow  and 
laborious  process  of  lifting  the  water  from  the  Nile  with  a 
well-sweep  or  shadoof,  and  it  is  also  watered  by  means  of 
great  irrigation  projects  planned  and  constructed  under  the 
direction  of  the  ablest  irrigation  engineers  England  could 
summon  into  her  service. 

In  the  Euphrates  Valley  in  Asia  are  remnants  of  irrigation 
systems  far  antedating  any  in  recorded  history.  These 
systems  were,  in  many  respects,  elaborate  and  complete. 
They  represented  an  immense  amount  of  labor,  together 
with  a  knowledge  of  engineering  problems  that  we  of  this 

142 


IRRIGATION  AND  DRAINAGE  143 

day  find  difficult  to  ascribe  to  so  remote  a  civilization. 
Cities  were  built  up  and  entire  areas  developed,  whose 
inhabitants  relied  solely  for  subsistence  on  these  irrigation 
works.  The  remains  of  these  ancient  systems  can  still  be 
traced  in  sufficient  detail  to  give  an  idea  of  their  extensive- 
ness  and  efficiency. 

In  America  irrigation  was  practiced  by  some  Indian  tribes 
(or  nations)  long  before  the  earliest  white  man  set  foot  on 
the  continent.  In  parts  of  New  Mexico  there  remain  to  the 
present  day  irrigation  systems  which  are  abundant  testimony 
to  the  skill  and  foresight  of  these  inhabitants.  Canals  still 
in  a  fair  degree  of  preservation  extend  many  miles  around 
and  across  plateaus,  connecting  the  sources  of  water  with  the 
places  where  it  was  to  be  applied.  For  designing  works 
of  this  sort,  these  aborigines  possessed  no  instruments  such 
as  we  have  today  for  the  making  of  precise  measurements. 
They  adopted  the  device  of  filling  the  ditches  with  water 
as  they  dug,  being  guided  in  this  way  as  to  the  route  which 
the  canal  was  to  follow.  The  results  were  ditches  of  marvel- 
ously  even  grade. 

234.  Recent  irrigation. — Irrigation  in  America  under  the 
regime  of  the  white  man  may  be  said  to  have  begun  with 
the  Mormon  settlement  of  Utah.    Smythe,  in  his  book  The 
Conquest  of  Arid  America,  gives  an  exceedingly  interesting 
account   of  the  way  in  which  these  Mormon  wanderers 
reclaimed  an  unpromising  desert  and  made  of  it  one  of  the 
most  fertile  regions  of  the  United  States.    For  a  full  account 
of  this  pioneer  effort  in  irrigation,  the  student  is  referred  to 
Smythe's  book. 

235.  Reclamation  service. — In  1912,  during  the  presidency 
of  Theodore  Roosevelt,  the  United  States  Government  for 
the  first  time  definitely  adopted  the  great  policy  which  led 
to  the  establishment  of  the  Reclamation  Service.    Briefly 
stated,  it  was  this:  The  Government  stands  ready  to  finance 
and  execute  projects  in  irrigation  and  drainage  which  in  the 


144  HORTICULTURE  FOR  SCHOOLS 

judgment  of  its  engineers  are  practicable  and  which  on 
account  of  the  time  and  money  involved  would  be  out  of  the 
question  for  private  capital.  Along  these  lines  some  notable 
undertakings  have  been  carried  to  completion.  The  immense 
amounts  of  money  and  the  engineering  skill  required  were 
not  available  to  any  individual  or  the  ordinary  corporation, 
and  the  Reclamation  Service  performed  a  task  which  other- 
wise would  perforce  have  gone  undone.  How  great  have 
been  the  benefits  the  following  statistics  will  abundantly 
show.  At  the  beginning  of  the  year  1920  a  total  area  of 
18,191,716  acres  had  been  put  under  irrigation.  The  value 
of  products  obtained  from  these  farms  in  1919  reached  the 
vast  total  of  $801,005,326. 

236.  Irrigation  in  humid  regions. — In  one  sense,   and 
especially  in  some  localities,  irrigation  is  a  form  of  insurance. 
Rainfall  may  be  abundant,  if  the  total  annual  precipitation 
is  taken  into  account.    But  it  may  be  lacking  at  those  times 
when  it  is  most  critically  needed;   and  an  irrigation  plant 
would  justify  itself  even  though  it  might  be  used  only  at 
long  intervals.    It  is  on  this  basis  that  provision  for  irriga- 
tion has  been  made  on  many  farms  in  the  humid  sections 
of  the  United  States. 

237.  Sources  of  water. — Water  may  be  secured  from 
mountain  streams  by  the  simple  process  of  diversion  to 
canals;   or  it  may  be  stored  in  reservoirs  during  the  rainy 
season,  and  this  supply  may  then  be  drawn  on  as  needed; 
or  it  may  be  obtained  from  the  underground  supply. 

238.  Diversion  of  streams  constitutes  the  most  obvious 
means  of  obtaining  water.    Immense  quantities  of  water  are 
carried  constantly  in  the  rivers  that  flow  to  the  seven  seas 
of  the  world,  and  if  this  could  be  utilized  in  the  growing  of 
crops  the  gain  to  mankind  would  be  very  great  indeed. 

There  are  many  examples  in  the  United  States  of  diversion 
of  stream  flow  on  a  large  scale.  The  Uncompahgre  project 
in  Colorado  is  one  of  the  largest  in  the  history  of  irrigation 


IRRIGATION  AND  DRAINAGE  145 

in  America.  Because  of  the  problems  encountered,  it  is  also 
of  intense  interest. 

Two  river  valleys  in  Colorado,  the  Gunnison  and  Uncom- 
pahgre,  lie  parallel.  The  Gunnison  River  carries  a  large 
amount  of  water  and  it  flows  through  a  narrow  precipitous 
canyon,  offering  no  opportunities  for  agriculture.  The 
Uncompahgre  River  carries  a  very  small  amount  of  water, 
but  flows  through  a  broad  and  fertile  valley,  promising  large 
opportunities  for  agricultural  development.  The  project 
which  the  United  States  Government  undertook  was  to  bore 
a  tunnel  through  a  range  of  hills  separating  the  two 
valleys;  and  through  this  tunnel  to  divert  the  water  from 
the  Gunnison  River,  using  it  to  irrigate  the  Uncompahgre 
Valley. 

In  the  prosecution  of  this  work,  problem  after  problem 
was  encountered  that  could  not  have  been  foreseen.  To 
begin  with,  the  task  was  one  of  great  magnitude.  Not  only 
was  the  tunnel  a  stupendous  problem  in  itself,  because  of  its 
size,  it  being  six  and  one-half  miles  long;  but  in  addition, 
intake,  canal,  and  distributing  systems  had  to  be  constructed. 
As  the  boring  of  the  tunnel  progressed,  unexpected  problems 
arose.  Large  quantities  of  water  and  of  carbon  dioxide  gas 
were  encountered.  At  one  point  extensive  layers  of  gravel 
and  sand  were  found  where  solid  rock  had  been  expected; 
and  the  tunnel  had  to  be  lined  with  a  thick  wall  of  concrete. 
Work  was  begun  in  February,  1905,  but  the  tunnel  was  not 
completed  until  January,  1910. 

239.  Imperial  Valley. — The  bringing  of  water  to  the 
Imperial  Valley  in  California  is  one  of  the  best  known 
irrigation  projects  ever  undertaken  in  the  United  States. 
The  irrigation  of  this  valley  was  first  attempted  by  private 
capital  in  the  year  1900.  In  the  view  of  the  men  who  under- 
took the  project,  their  problem  was  comparatively  simple. 
They  diverted  the  water  from  the  Colorado  River  by  means 
of  a  canal  which  tapped  the  stream,  as  the  Colorado  is  a 


146  HORTICULTURE  FOR  SCHOOLS 

large  river  with  a  fairly  continuous  flow  during  the  summer 
season  when  demands  for  water  are  heaviest. 

The  Imperial  Valley  is  bounded  on  east  and  west  by 
mountains  and  on  the  southeast  by  the  Colorado  River. 
Since  the  land  slopes  in  a  northwesterly  direction  from  the 
river  to  the  Salton  Sea,  it  seemed  simple  to  divert  a  small 
portion  of  the  stream  into  canals  and  carry  it  over  the  valley 
for  irrigation  purposes.  One  geological  factor,  however,  the 
builders  failed  to  take  into  account.  The  Colorado  River 
flows  along  what  has  been  described  as  the  top  of  a  hill. 
Like  the  Mississippi,  the  water  level  of  the  stream  is  higher 
than  the  adjacent  country,  with  the  resulting  danger  of 
overflow  in  times  of  flood.  In  the  northern  end  of  the 
Imperial  Valley  is  the  Salton  Sea,  a  body  of  water  between 
two  and  three  hundred  feet  below  sea-level.  In  past  cen- 
turies the  Colorado  overflowed  its  banks,  thereby  cutting 
a  new  channel,  and  flowed  into  the  region  of  the  Salton  Sea. 
When  this  region  became  filled  with  water,  the  Colorado  was 
again  forced  to  send  its  streams  to  the  Gulf  of  California  and 
in  the  course  of  time  built  up  with  its  sediment  a  bank 
which  cut  off  the  outlet  into  the  Imperial  Valley  region. 
This  happened  not  once  but  many  times,  the  region  of  the 
Imperial  Valley  being  successively  an  extension  of  the  Gulf 
of  California,  an  inland  lake,  and  a  dried  up  lake-bed;  this 
process  being  repeated  again  and  again. 

In  the  spring  of  1906  the  engineers  in  charge  of  the  irriga- 
tion project  were  repairing  the  intake  which  diverted  the 
waters  of  the  Colorado  into  the  Imperial  irrigation  system. 
Unfortunately,  the  usual  spring  flood  came  this  year  several 
months  sooner  than  was  expected,  with  the  result  that  the 
workers  were  forced  to  abandon  the  intake  while  it  was 
still  in  an  uncompleted  condition.  A  considerable  portion 
of  the  now  swollen  river  immediately  sought  this  new  outlet, 
flowing  down  through  the  valley  and  into  the  Salton  Sea.  It 
Was  only  by  most  strenuous  efforts  and  after  the  expenditure 


IRRIGATION  AND  DRAINAGE  147 

of  large  sums  of  money  in  constructing  a  temporary  rock 
dam  that  the  flood  was  finally  controlled  and  the  valley  saved. 
Since  that  time,  ownership  of  the  irrigation  system  has 
been  gradually  taken  over  by  the  settlers  themselves,  until 
the  actual  users  of  the  water  are  also  the  owners  of  the 
system. 

240.  Diversion  of  small  streams. — This  same  process  of 
diversion  of  stream  flow  is  practiced  on  a  small  scale,  also, 
in  many  parts  of  the  country.     Concrete  pipe  is  rapidly 
taking  the  place  of  the  old  open  ditch.    It  is  a  little  more 
expensive  in  the  beginning,  but  saving  in  labor  and  water 
soon  makes  up. 

241.  Storage  reservoirs  serve  a  two-fold  purpose.    They 
store  up  water  for  use  when  needed  on  farm  and  orchard; 
and  they  regulate  stream  flow,  thereby  lessening  the  danger 
from  destructive  floods. 

The  Elephant  Butte  reservoir  in  Texas  is  one  of  the 
largest,  if  not  the  largest,  storage  reservoirs  in  the  world. 
It  impounds  enough  water  to  cover  between  two  and  three 
million  acres  to  a  depth  of  one  foot.  Another  large  project 
is  the  Roosevelt  dam  in  Arizona,  located  on  the  Salt  River 
near  its  junction  with  Tonto  Creek,  about  seventy-eight 
miles  northeast  of  Phoenix.  It  impounds  1,284,000  acre-feet 
of  water  which  is  used  in  irrigating  the  farming  lands  of  the 
Salt  River  Valley  in  central  Arizona. 

242.  The  underground  water  supply. — As  a  rule,  water 
is  obtained  from  this  source  by  means  of  pumps.    The  power 
employed  depends  on  the  amount  of  water  desired  and  forms 
of  energy  available.    Those  most  frequently  utilized  are  wind, 
electricity,  and  the  products  of  petroleum,  such  as  gasoline, 
kerosene,  and  similar  substances.    There  is  a  definite  limit 
to  the  height  to  which  water  can  be  raised  at  a  profit,  depend- 
ing on  cost  of  installation  and  operation  of  pumping  plant, 
increased  return  secured  by  irrigation,  and  value  of  the 
final  product. 


148  HORTICULTURE  FOR  SCHOOLS 

In  a  few  localities  water  may  be  obtained  in  considerable 
quantities  without  pumping,  since  artesian  wells  may  be 
secured  merely  by  tapping  the  underground  supply.  It  is  a 
cheap  method  of  obtaining  water  but  is  usually  unreliable, 
for  when  any  considerable  number  of  wells  is  sunk,  the  flow 
is  likely  to  dwindle  or  cease  in  all  of  them.  Artesian  wells 
are  caused  by  the  water  being  held  in  the  ground  under 
pressure  by  impervious  strata  of  soil  or  rock  material;  and 
when  this  is  pierced  the  water  is  allowed  to  escape.  If  the 
supply  is  exhausted  faster  from  the  wells  than  it  flows  into 
the  underground  reservoir,  the  flow  will,  of  course,  soon  cease. 

243.  Application  of  water. — Water  is  applied  to  the 
ground  by  flooding,  basins,  furrows,  sub-irrigation,  or  over- 
head sprinkling.  The  method  depends  primarily  on  the  crop 
and  the  soil.  Vegetables  are  frequently  grown  in  beds  pro- 
vided with  systems  of  underground  tiles  through  which 
water  is  introduced  into  the  soil.  The  method  is  practicable 
only  for  crops  grown  on  a  relatively  small  scale  or  for  green- 
house irrigation,  but  it  is  an  efficient  means  of  applying  the 
water  and  it  leaves  the  surface  of  the  ground  loose  and 
pliable. 

Sometimes  vegetables  are  grown  in  beds  depressed  below 
the  general  level  of  the  ground,  and  are  irrigated  by  flooding. 
This  is  on  a  small  scale  the  basin  method  of  application  of 
water.  Sometimes,  also,  vegetables  are  grown  on  narrow 
flats  somewhat  higher  than  the  ground  level,  and  are  irri- 
gated by  lateral  seepage  from  either  side. 

Irrigation  by  sprinkling  has  come  into  extensive  use  in 
recent  years.  Permanent  pipes  are  used,  and  large  areas 
are  watered  by  the  simple  process  of  opening  a  valve.  The 
method  is  very  successful.  The  only  question  is  the  original 
cost  of  installation. 

Orchards  are  most  frequently  irrigated  by  the  furrow 
method.  Water  is  conveyed  through  a  head-ditch  along  the 
highest  side  of  the  land,  and  then  distributed  over  the 


IRRIGATION  AND  DRAINAGE  149 

orchard  as  shown  in  Plate  V.  The  method  is  familiar  where- 
ever  irrigation  is  practiced,  but  there  are  still  many  unsolved 
questions  connected  with  it.  For  example,  the  best  length 
of  furrow  depends  on  the  character  of  soil;  a  light  soil  requires 
a  relatively  short  furrow,  while  the  reverse  is  true  with  a 
clay  or  adobe  soil.  Frequency  of  irrigation  is  another 
unsettled  question,  the  interval  varying  from  a  week  or  ten 
days  to  one  or  even  two  months.  The  amount  of  water  to 
be  applied  is  another  serious  problem.  Much  investigation 
must  still  be  done  before  these  questions  will  finally  be 
answered  to  the  best  interests  of  the  horticulture  of 
America. 

244.  Water  measurement. — Quantity  of  water  may  be 
designated  in  a  variety  of  ways;  it  is  most  frequently  given 
in  cubic  feet,  gallons,  acre-inches,  acre-feet,  cubic  feet  a 
second  (called  second-feet),  and  miner's  inches.    Cubic  feet 
and  gallons  are  units  commonly  employed  to  designate  the 
amount  of  water  in  a  storage  reservoir.    An  acre-foot  sig- 
nifies the  water  on  an  acre  of  land  if  it  be  a  foot  deep ;  since 
an  acre  contains  43,560  square  feet,  an  acre-foot  is,  there- 
fore, equivalent  to  43,560  cubic  feet.    The  acre-inch  is  the 
most  convenient  measure  of  an  irrigation.    An  application 
of  2%  acre-inches  means  that  the  piece  of  land  in  question 
received  water  equivalent  to  a  rainfall  over  the  entire  piece 
of  2^4  inches.     To  change  acre-inches  to  acre-feet,  divide 
by  12;   vice  versa,  to  change  acre-feet  to  acre-inches,  mul- 
tiply by  12.    One  acre-inch  equals  3630  cubic  feet  or  27,150 
gallons.    This  weighs  226,392  pounds,  or  113.2  tons.    To 
change  acre-inches  to  cubic  feet,  multiply  the  number  of 
acres  in  question  by  3630,  and  multiply  this  by  number  of 
acre-inches. 

245.  Miner's  inch. — The   common  measure  of  stream 
flow  is  the  miner's  inch.    This  unit  varies  somewhat  in  dif- 
ferent states;  but  is  commonly  accepted  to  mean  the  amount 
of  water  flowing  through  an  opening  1  inch  square,  with  the 


150 


HORTICULTURE  FOR  SCHOOLS 


water  maintained  at  a  constant  level  4  inches  above  the 
center  of  the  opening.  This  is  equal  to  ^  cubic  foot  a 
second,  or  1^  cubic  feet  a  minute.  Since  1  cubic  foot  con- 
tains 7.48  gallons,  it  fol- 
lows that  1  miner's  inch 
delivers  practically 
9  gallons  a  minute. 

246.  Weir  meas- 
urement.— A  n  o  t  h  e  r 
very  common  device 
for  calculating  stream 
flow  is  known  as  the 
weir;  but  this  is 
limited  in  its  usefulness 
to  comparatively  small 
streams.  It  is  com- 
monly constructed  of 
wood,  faced  with  met- 
al, especially  along  the 
crest  of  the  weir.  In 
calculating  stream 
flow,  the  observer 
takes  the  depth  of 
water  flowing  over  the 
crest  of  the  weir,  being 
careful  to  secure  the 
reading  at  a  point  far 
enough  back  to  avoid 
the  curved  surface 
which  is  formed  as 
the  water  flows  over 
the  crest.  This  reading 
can  then  be  changed  to  cubic  feet  a  second  by  using  the  table 
on  page  156. 
The  Gippoletti  weir  was  invented  by  an  Italian  of  that 


IRRIGATION  AND  DRAINAGE  151 

name  (Fig.  98).  For  each  inch  of  height  the  sides  slope 
back  J4:  inch  on  each  side.  That  is,  if  the  height  is  8  inches, 
and  if  the  width  at  the  bottom  20  inches,  then  the  width  at 
the  top  will  be  20  plus  2  plus  2  equals  24  inches. 

Certain  precautions  are  necessary  in  the  construction  of 
this  weir.  The  distance  from  the  crest  of  the  weir  to  the 
bottom  of  the  canal  or  floor  of  the  weir  box  should  be  at 
least  three  times  the  depth  of  water  flowing  over  the  weir. 
The  bottom  and  sides  of  the  weir  notch  should  be  beveled 
on  the  downstream  side  to  give  a  narrow  edge.  Water 
should  approach  the  weir  with  a  velocity  not  greater  than  six 
inches  a  second.  The  water  passing  over  the  weir  should  have 
a  free  overfall.  An  ample  distance  must  be  left  between  the 
ends  of  the  weir  crest  and  the  sides  of  the  ditch  or  weir  box. 

247.  Water  rights. — In  almost  all  agricultural  localities 
water  is  scarce  some  of  the  time;  and  in  the  arid  parts  of 
the  country  it  is  deficient  all  the  time.  It  is,  therefore, 
valuable  to  the  user,  and  to  protect  him  and  assure  him  of 
undisputed  right  to  his  fair  share,  the  law-making  bodies  of 
the  several  states  have  drawn  up  an  elaborate  code  of  water 
rights.  These  are  in  many  cases  of  very  great  value,  exceed- 
ing that  of  the  land  itself.  They  depend  to  some  extent  on 
priority  of  claim.  "First  come,  first  served"  is  the  principle 
on  which  such  rights  are  based.  But  there  is  a  growing 
tendency  in  America  to  base  the  right  to  water  on  the  use 
of  it.  Water,  according  to  this  view,  is  a  natural  resource 
the  ownership  of  which  is  given  over  to  those  who  will 
render  in  return  the  largest  service  to  society. 

Riparian  rights,  recognized  in  some  states  but  not  in 
others,  are  based  on  a  different  principle;  that  is,  on  the 
assumption  that  the  farms  touching  the  streams  have  a 
prior  right  to  the  water.  Such  rights  have  given  rise  to  many 
forms  of  injustice  and  are  difficult  of  legal  supervision. 

The  entire  matter  of  water  right  legislation  is  growing 
increasingly  complex  and  important;  for  as  the  demand 


152  HORTICULTURE  FOR  SCHOOLS 

for  the  water  increases,  its  value  grows  in  proportion,  and 
adjustments  that  are  fair  to  all  become  more  and  more 
difficult.  The  problem  applies  not  only  to  water  diverted 
from  streams  or  stored  in  reservoirs,  but  to  the  underground 
water  as  well. 

248.  Moderation  in  irrigation. — Too  much  water  may 
be  as  disastrous  in  irrigation  practice  as  too  little.    "The 
best  way  to  irrigate,"  says  one  writer,  "is  with  a  rake," 
meaning  that  the  best  method  to  conserve  moisture  is  by 
frequent  and  thorough  cultivation.     But  where  irrigation 
water  is  abundant  and  cheap,  the  temptation  is  always 
present  to  use  the  water  rather  than  the  cultivator.    This 
causes  poor  soil  conditions,  a  rising  water-table  or  the  wast- 
ing of  plant-food  through  leaching.     These  serious  conse- 
quences are  in  many  cases  preventable,  and  serve  as  stern 
reminders  of  the  necessity  of  intelligence  in  the  use  of  irriga- 
tion water. 

249.  Alkali. — All  water  that  has  flowed  over  or  through 
the  ground  carries  a  greater  or  less  .quantity  of  mineral 
salts  in  solution.    When  the  water  is  evaporated  by  the  sun, 
the  mineral  salts  are  left  behind,  and  these  give  rise  to  the 
so-called  alkali  soils.     There  is  especial  danger  from  this 
source  in  irrigated  regions,  for  such  localities  are  receiving 
fresh  supplies  of  mineral  salts  with  each  irrigation.    In  regions 
of  abundant  rainfall,  the  excess  water  would  wash  the  ground 
free  from  these  salts;   but  in  arid  or  semi-arid  climates  the 
matter  accumulates  year  after  year  and  decade  after  decade, 
becoming  always  more  concentrated. 

There  is  only  one  practical  way  to  remove  alkali  and  that  is 
by  drainage.  Tiles  are  employed  for  the  purpose  in  the  same 
way  that  they  are  used  in  other  regions  for  carrying  off  surplus 
water;  and  already  the  matter  of  tile  drainage  is  coming  up 
for  serious  consideration  in  many  of  the  irrigated  parts  of 
the  United  States. 

250.  Drainage  has  for  a  long  time  been  recognized  as  of 


IRRIGATION  AND  DRAINAGE  153 

primary  importance.  In  many  sections  of  the  United  States 
it  is  resorted  to  not  only  in  the  regions  of  heavy  rainfall,  but 
also  in  localities  where  rainfall  is  very  slight.  By  means  of 
drainage,  vast  areas  which  otherwise  would  have  been  second 
rate  or  worthless  have  been  transformed  into  land  of  high 
producing  power.  The  subject  is,  therefore,  as  worthy  of 
consideration  in  some  respects  as  is  irrigation  with  which  it 
is  commonly  associated. 

251.  Why  drainage  is  important. — In  many  sections  of 
the  United  States,  the  rainfall  is  excessively  heavy,  with  the 
result  that  the  soil  is  saturated  with  moisture  much  of  the 
time.  Under  these  conditions,  the  decay  of  vegetation  and 
other  chemical  processes  is  not  carried  to  completion  and  a 
large  number  of  injurious  substances  results.  Among  other 
things,  it  is  a  very  common  phenomenon  in  wet  soils  for 
acids  of  one  sort  or  another  to  be  formed.  When  this  hap- 
pens, the  soil  is  said  to  be  sour.  A  few  plants  like  the  cran- 
berry thrive  on  this  type  of  land,  but  most  plants  require  a 
soil  where  acid  is  absent. 

The  first  step  in  correcting  this  acid  condition  is  to  remove 
the  excess  water  from  the  soil.  The  next  step  is  the  applica- 
tion of  lime,  which  reacts  chemically  with  the  acid  of  the 
soil,  neutralizes  it,  and  leaves  the  land  in  a  non-acid  condition. 

The  soil  is  not  dead  and  inert  as  is  so  commonly  supposed, 
but  is  teeming  with  myriads  of  forms  of  life.  It  is  also  a 
laboratory  in  which  many  and  very  complex  chemical 
reactions  are  taking  place  continually.  The  best  conditions 
for  the  life  of  the  soil  are:  (1)  an  optimum  amount  of  water, 
and  (2)  a  plentiful  supply  of  atmospheric  oxygen.  If  the 
land  is  too  dry,  the  optimum  of  water  is  not  present  and 
conditions  are  poor  for  bacterial  and  chemical  activity.  If, 
on  the  other  hand,  there  is  too  much  water  in  the  soil,  then 
the  oxygen  of  the  air  is  excluded  and  many  of  the  bacterial 
and  chemical  changes  are  shortened  on  that  account.  Irriga- 
tion supplies  water  in  such  a  way  as  to  keep  as  near  as  possible 


164  HORTICULTURE  FOR  SCHOOLS 

the  optimum  condition  as  regards  moisture.  Drainage 
removes  excess  water  and  thus  allows  the  necessary  atmos- 
pheric oxygen  to  enter. 

252.  Drainage  of  swamp  lands. — There  are  large  areas 
in  the  United  States  where  the  topographical  conditions  are 
such  that  water  collects  year  after  year,  forming  swamps. 
These  areas  are  commonly  very  rich  in  natural  soil  fertility, 
for  plant-food  has  accumulated  here  for  centuries  and  very 
frequently  organic  matter  has  been  added  in  large  quantities. 
The  drainage  of  these  lands  is  an  engineering  problem  which 
offers  in  many  cases  great  inducements  to  the  capitalist  or  the 
state;  financial  returns  are  more  or  less  certain  once  drain- 
age has  been  accomplished.     On  that  account,  large  areas 
have  been  reclaimed  and  are  now  under  cultivation.     At 
the  present  time  there  are  still  many  thousands  of  acres  of 
such  lands,  especially  in  the  South.    When  this  task  is  com- 
pleted, a  two-fold  good  will  have  been  accomplished:    a 
menace  to  health  in  the  vicinity  of  these  swamps  will  have 
been  removed,  and  large  areas  of  land  will  have  been  put  to 
productive  use. 

253.  Drainage   in  irrigated  regions. — In  many  of  the 
irrigated  sections  of  the  United  States,  drainage  is  coming  to 
be  quite  as  important  as  in  regions  of  too  abundant  rainfall. 
It  has  been  found  that  irrigation  water,  applied  year  after 
year,  very  frequently  soaks  into  the  soil  in  such  large  quan- 
tities that  the  water-table  below  the  surface  rises  until  it 
becomes  a  menace  to  the  growing  crops.    This  is  especially 
true  if  the  more  deep-rooted  plants  like  fruit-trees  are  grown. 
There  are  two  ways  of  overcoming  this  difficulty.    One  is  by 
application  of  less  water.    This  can  frequently  be  brought 
about  through  more  intensive  conservation  of  the  moisture 
already  in  the  soil.     When,  in  spite  of  this,  the  moisture 
becomes  excessive,  the  only  practical  remedy  is  to  drain  off 
the  excess  through  underground  tiles. 

254.  The  necessity  for  irrigation  and  drainage. — The 


IRRIGATION  AND  DRAINAGE  155 

time  of  free  lands  is  past.  During  the  nineteenth  century,  a 
continent  was  to  be  had  for  the  asking.  When  anyone  in 
America  wanted  a  farm,  all  he  had  to  do  was  to  go  out  to  the 
West  and  settle  on  one.  Those  opportunities  are  gone, 
never  to  return.  The  land  is  definitely  limited  in  quantity 
and  in  productivity.  We  must,  therefore,  make  the  very 
best  use  of  it,  reclaim  it  if  possible  where  it  lies  waste,  and  put 
it  into  the  highest  possible  state  of  productivity.  This  is  the 
great  problem  which  the  American  farmer  faces  today.  In 
the  solution  of  this,  irrigation  and  drainage  play  a  large  part. 
255.  Horticulture  and  irrigation  go  hand  in  hand.  Many 
of  the  finest  fruit  regions  of  America  have  been  made  possible 
by  artificial  application  of  water  to  land.  Deserts  have  been 
reclaimed  and  waste  places  made  to  blossom  and  bear  fruit  by 
the  magic  of  the  irrigation  ditch.  But  the  real  problems 
lie  yet  ahead.  In  no  type  of  farming  is  there  such  imperative 
need  of  intelligence  and  forethought,  for  the  difficulties  are 
many,  and  they  must  be  met  and  solved.  The  student  who  is 
considering  these  problems  no  wean  be  assured  that  he  is  grap- 
pling with  questions  worthy  of  a  lifetime  of  thoughtful  study. 

EXERCISES 

EXERCISE  I. — Constructing  Cippoletti  weir,  and  measuring  stream  flow. 

Materials. — One-inch  board  six  inches  wide  and  about  three  feet  long; 
saw;  pencil;  ruler;  level;  wooden  peg  one  foot  long. 

Procedure. — For  this  exercise  use  any  small  stream  in  the  neighbor- 
hood. If  no  natural  stream  is  available,  produce  an  artificial  one  by 
turning  on  the  garden  hydrant.  The  size  of  the  weir  constructed 
will  be  determined  by  the  size  of  the  stream  available  for  measurement. 

In  accordance  with  description  given  in  the  body  of  the  text,  construct 
a  Cippoletti  weir.  Set  this  board  in  a  furrow  in  such  a  way  that  it  will 
act  as  a  dam,  causing  the  watej  to  flow  over  the  crest  of  the  weir.  Drive 
a  peg  in  the  furrow  on  the  upper  side  of  the  weir  to  such  a  depth  in  the 
ground  that  the  top  of  the  peg  is  level  with  the  crest  of  the  weir.  Turn 
water  down  the  furrow  and  allow  it  to  flow  (but  at  not  too  great  speed) 
over  the  crest  of  the  weir.  The  peg  should  be  so  located  that  it  is 
covered  by  the  water  impounded  by  this  miniature  dam.  After  the 


156 


HORTICULTURE  FOR  SCHOOLS 


water  has  been  flowing  for  a  short  time  over  the  crest  of  the  weir,  measure 
the  depth  of  water  over  the  top  of  the  peg  with  a  ruler  and  determine 
from  the  following  table  the  number  of  miner's  inches  of  stream  flow: 


Depth  in  inches 
of  water  flowing 
over  weir 

Miner's  inches 
flowing  over  each 
inch  of  weir  in 
length 

Depth  in  inches 
of  water  flowing 
over  weir 

Miner's  inches 
flowing  over  each 
inch  of  weir  in 
length 

Depth  in  inches 
of  water  flowing 
over  weir 

Miner's  inches 
flowing  over  each 
inch  of  weir  in 
length 

Depth  in  inches 
of  water  flowing 
over  weir 

Miner's  inches 
flowing  over  each 
inch  of  weir  in 
length 

H 

.01 

m 

2.56 

7*A 

7.04 

12^ 

15.27 

% 

.04 

4 

2.69 

7% 

7.22 

13 

15.72 

% 

.07 

43/6 

2.81 

7K 

7.40 

13M 

16.18 

Yt 

.12 

4% 

2.93 

8 

7.58 

131^ 

16.64 

5A 

.17 

43/g 

3.07 

gi/g 

7.76 

13% 

17.10 

ZA 

.22 

4J^ 

3.19 

8M 

7.93 

14 

17.57 

% 

.27 

4% 

3.33 

8% 

8.12 

14/4 

18.04 

i 

.33 

m 

3.47 

8^ 

8.30 

14% 

18.52 

\y% 

.39 

47A 

3.61 

8% 

8.48 

14% 

19.00 

1/4 

.46 

5 

3.75 

8% 

8.67 

15 

19.48 

1% 

.54 

5^8 

3.89 

8%, 

8.86 

15^4 

19.98 

\1A 

.62 

5% 

4.03 

9 

9.05 

15% 

20.47 

1% 

.69 

5^8 

4.18 

9^ 

9.23 

15^4 

20.97 

1% 

.77 

51A 

4.32 

9/4 

9.42 

16 

21.47 

\y% 

.86 

&A 

4.47 

9//8 

9.62 

16% 

22.47 

2 

.95 

5% 

4.62 

91^ 

9.81 

17 

23.50 

2% 

.04 

57A 

4.77 

9^8 

10.00 

17% 

24.54 

2% 

.13 

6 

4.92 

9% 

10.19 

18 

25.58 

2^8 

.22 

6^8 

5.08 

9% 

10.39 

18% 

26.65 

2/^ 

.32 

6% 

5.24 

10 

10.59 

19 

27.74 

2/^ 

.42 

6% 

5.39 

10^4 

10.99 

19% 

28.83 

2% 

.52 

6J^ 

5.54 

10^ 

11.39 

20 

29.95 

2K 

.62 

6% 

5.71 

10^ 

11.80 

20^ 

32.07 

3 

.74 

6% 

5.87 

11 

12.22 

21 

33.21 

3^i 

.86 

6% 

6.04 

11/4 

12.65 

21% 

34.36 

3% 

.97 

7 

6.20 

11)^ 

13.06 

22 

35.52 

3% 

2.08 

7^8 

6.37 

11% 

13.50 

22^ 

36.70 

3^ 

2.19 

7% 

6.53 

12 

13.94 

23 

37.90 

3% 

2.31 

7% 

6.70 

12% 

14.38 

23^ 

38.10 

8K 

2.43 

7y* 

6.87 

1234 

14.82 

24 

39.32 

IRRIGATION  AND  DRAINAGE  157 

EXERCISE  II. — Irrigation  in  the  United  States. 

Materials. — Books  on  irrigation;  encyclopaedia  and  magazine  articles 
and  Government  bulletins  dealing  with  this  topic;  also  weather  maps 
of  the  United  States. 

Procedure. — Using  such  sources  of  information  regarding  irrigation 
projects  as  are  available  in  your  institution,  sketch  on  Weather  Bureau 
maps  or  similar  outline  maps  of  the  United  States,  the  location  of  the 
principal  irrigation  projects  of  this  country. 

EXERCISE  III. — Irrigation  problems. 

1.  What  is  an  acre-inch? 

2.  How  many  square  feet  are  there  in  an  acre? 

3.  How  many  cubic  feet  of  water  are  contained  in  one  acre-inch? 

4.  What  is  meant  by  a  "second-foot?" 

5.  What  is  the  relation  between  a  second-foot  and  a  miner's  inch? 

6.  How  many  second-feet  are  delivered  by  a  stream  of  fifty  miner's 
inches  flowing  for  one  hour? 

7.  What  relation  is  there  between  this  and  one  acre-inch? 

8.  Utilizing  the  answer  to  the  above  question,  answer  the  following 
questions: 

a.  How  many  acre-inches  will  a  stream  of  50  miner's  inches  deliver 
to  10  acres  of  ground  in  24  hours?    The  volume  of  a  circular  reservoir 
with   perpendicular   sides  is   ascertained  according  to   the  following 
formula: 

V  equals  7rr2H 
TT   equals  3.1416 
r   equals  radius  of  circle 
H  equals  Height 

b.  How  many  cubic  feet  in  a  circular  reservoir  with  a  radius  of 
50  feet  and  a  height  of  10  feet? 

c.  If  a  river  has  a  flow  of  1000  second-feet,  how  many  acres  will 
it  irrigate  with  five  acre-inches  of  water  during  a  period  of  thirty  days? 


CHAPTER  XII 
POLLINATION  AND  FERTILIZATION 

POLLINATION  and  fertilization  are  essential  to  the  formation 
of  seed,  and  the  development  of  seed  is  necessary,  in  most 
cases,  to  the  production  of  good  fruit.  A  few  kinds  of  seed- 
less fruits  have  proved  satisfactory,  of  which  the  seedless 
grape  and  certain  varieties  of  the  orange  are  very  valuable 
examples.  The  banana  is  also  seedless,  as  is  the  pineapple. 
But  with  most  fruits  the  seed  and  pulp  must  develop  simul- 
taneously. It  is  only  in  comparatively  recent  times  that  the 
commercial  importance  of  the  subject  of  pollination  and 
fertilization  has  been  realized  and  that  a  careful  study  has 
been  made  of  its  relation  to  fruit  production. 


Anther 


Fia.  99. — Cherry  blossom. 

256.  The  flower  and  its  parts. — To  understand  the  nature 
of  pollination  and  fertilization,  one  must  first  be  familiar 
with  the  structure  of  the  flower.  In  Fig.  99  is  shown  a  cherry 
blossom  with  the  various  parts  labeled.  On  the  outside  is  a 

1.58 


POLLINATION  AND  FERTILIZATION  159 

green-colored  member  known  as  the  calyx,  divided  into 
several  leaf-like  parts,  each  of  which  is  called  a  sepal.  The 
calyx  protects  the  young  flower-bud  from  insects,  winds, 
rain,  and  possibly  in  some  cases  from  cold.  Inside  of  the 
calyx  is  the  colored  showy  part  of  the  flower  known  as  the 
corolla,  the  divisions  of  which  are  called  petals.  The  bright 
colors  of  the  corolla  attract  bees  and  other  insects.  A 
further  examination  of  the  flower  reveals  a  number  of  slender 
members,  the  stamens,  or  male  organs  of  the  plants,  each 
consisting  of  a  thread-like  part  (the  filament)  and  a  knob- 
like  enlargement  (the  anther).  Pollen-grains  are  produced 
within  the  anthers.  The  pistil  or  female  part  of  the  cherry 
blossom  is  a  vase-shaped  organ  in  the  center  of  the  flower. 
The  somewhat  expanded  portion  of  the  top,  known  as  the 
stigma,  receives  and  holds  the  pollen-grain  at  the  opportune 
time  and  secretes  substances  to  cause  the  grain  to  ger- 
minate. At  the  bottom  of  the  pistil  is  a  bulge,  the  ovary  or 
seed  case,  which,  after  fertilization  has  taken  place,  holds  the 
developing  seed. 

257.  Pollination  and  fertilization. — Before  a  seed  can  be 
formed,  a  certain  cell  contained  in  the  pollen-grain  must  be 
brought  in  contact  with  a  particular  cell  in  the  ovary  so  that 
the  two  cells  may  unite  or  fuse.  When  the  pollen-grains  are 
mature,  the  anthers  crack  open  (dehisce)  and  liberate  them. 
They  then  fall  upon  or  are  carried  to  the  stigma.  The 
alighting  or  placing  of  the  pollen-grain  upon  the  stigma  is 
known  as  pollination. 

Soon  after  the  pollen-grain  has  alighted  upon  the  receptive 
stigma,  it  begins  to  swell  and  puts  forth  a  tube.  The  pollen- 
tube  continues  to  lengthen,  grows  down  the  style,  and 
finally  reaches  the  ovary  through  a  little  opening  called  the 
micropyle.  The  nucleus  is  then  discharged  from  the  tip  of 
the  pollen-tube,  and  fuses  with  the  female  nucleus  in  the 
ovary.  This  process  is  called  fertilization  (Fig.  100).  After 
the  two  cells  have  fused,  a  division  takes  place  (Fig.  101). 


160 


HORTICULTURE  FOR  SCHOOLS 


First  two  cells  are  formed,  next  four,  then  eight,  and  this 
dividing  continues  until  there  are  many  cells,  resulting 
finally  in  the  seed  with  its  embryo 
plant.  Pollination  and  fertilization, 
then,  are  both  necessary  for  the 
formation  of  seed. 

258.  Organs  essential  for  seed 
production. — Only  two  organs  are 
necessary  for  the  production  of  seed, 
the  pistil  (Fig.  102)  and  the  stamens. 
These,  therefore,  are  called  the  essen- 
tial organs  of  the  flower.  The  calyx 
and  corolla,  called  together  the 
perianth,  though  frequently  of  service, 
are  not  necessary  for  seed  production, 

and  in  flowers  of  many  pjants  either 

'  or  both  is  wanting.  While 
and  Pistils  are  necessary 
the  for  seed  production,  both  need  not 
be  present  in  the  same  flower  or 
even  on  the  same  plant.  A  flower  having  both  essential 
organs,  as  the  cherry  blossom,  is  said  to  be  perfect. 
One  possessing  either  stamens  or  pistils  but  not  both 
is  imperfect.  Flowers  possessing  stamens  only  are 
staminate,  and  those  having  pistils  only  are  pistillate.1 
When  stamens  and  pistils  are  borne  separately  in  different 
flowers  and  both  types  of  flowers  occur  on  the  same  indi- 
vidual, the  plant  is  monoecious.2  Such  a  plant,  of  course,  has 
no  perfect  flowers.  Indian  corn,  pumpkins,  cucumbers, 

1  The  strawberry  is  an  example  of  a  plant  possessing  these  various  types 
of  flowers.     Many  varieties  of  strawberry  plants  produce  perfect  flowers. 
Others  have  imperfect  blossoms,  containing  pistils  with  imperfect  or  very 
few  stamens.    Strawberry  plants  with  imperfect  flowers  containing  stamens 
only  are  rarely  found  because  staminate  flowers  do  not  produce  fruit  and 
plants  having  them  are  not  cultivated. 

2  "Monoecious"  means  belonging  to  one  household. 


POLLINATION  AND  FERTILIZATION 


161 


melons,  oaks,  pecans,  filberts,  walnuts,  and  butternuts  are 
monoecious.  When  a  plant  bears  either  staminate  or  pistillate 


£>  £  JT 

FIG.  101. — Multiplication  of  cells  after  fertilization. 

flowers,  but  not  both  kinds,  it  is  said  to  be  dioecious.1 
fras,  hops,  poplars,  willows,  date  palms,  and 
most  persimmons  are  dioecious. 

259.  Relation  of  pollination  and  fertilization 
to  the  se'tting  of  fruit. — While  the  seed  is 
developing,  its  surrounding  parts,  which  form 
the  edible  portions  of  most  orchard  fruits, 
are  also  evolving.  The  formation  of  the  ing  large 
seed  is  necessary  in  order  that  the  fruit  may  set  and  not 
drop  prematurely,  except  in  the  case  of  the  navel  orange, 
and  a  few  other  fruits. 

A  flower  is  said  to  be  self-pollinated  when  its  stigma  has 
received  pollen  from  a  flower  of  the  same  variety;  it  is 
cross-pollinated  when  the  pollen  comes  from  a  different 
variety.  Flowers  which  form  fruits  and  seeds  when  fer- 
tilized by  pollen  from  the  same  variety  are  said  to  be  self- 
fertile  and  the  process  is  known  as  self-fertilization.  Flowers 

1  "Dioecious"  means  belonging  to  two  households. 


162 


HORTICULTURE  FOR  SCHOOLS 


fertilized  by  pollen  from  some  other  variety  are  said  to  be 
cross-fertilized.  When  a  flower  will  not  set  seed  with  pollen 
from  itself  or  from  flowers  of  the  same  variety,  it  is  self-sterile. 
When  flowers  of  a  particular  plant  will  not  set  seed  with 
pollen  obtained  from  some  other  kind,  the  varieties  are  said 
to  be  inter-sterile. 

In  many  cases,  cross-pollination  with  the  consequent  cross- 
fertilization  results  in  the  best  seed,  as  well  as  in  a  heavier 
set  of  seed  and  fruits.  In  many  cases  also,  self-pollination 
will  not  result  in  fertilization  at  all,  so  that  it  is  necessary 
that  many  plants  have  flowers  with  arrangements  of  some 
kind  to  prevent  self-fertilization,  and  to 
encourage  cross-pollination  by  insects. 
These  devices  are  exceedingly  numerous, 
varied  in  structure,  and  interesting,  but 
cannot  be  described  here. 

260.    Requisites    for    fertilization. — In 
order   that   fertilization  may  take  place, 
both  the  pollen  and  the  pistil  must  meet 
certain    requirements.     The   pollen-grains 
(Figs.  103,  104)  must  be  viable,  that  is, 
they  must  be  capable  of  germinating,  of 
producing  a  tube,  and  a  cell  capable  of 
Flgrai1ns.3'A7.K?effer  uniting  with  the  egg-cell  of  the  ovary. 
moni;Bc?^idp^p^      Many  factors  affect  the  viability  of  pollen : 

D,acabia;E,hazefnut.     (1)  pollen  mugt  be  mature.      It  must  have 

reached  a  certain  age  and  passed  through  a  definite  period  of 
development  before  it  can  germinate  and  fertilize  the  ovule. 
This  development  takes  place  within  the  anther,  which,  as  we 
have  seen,  cracks  open  at  the  proper  time  and  liberates  the 
pollen-grains.  On  the  other  hand,  pollen-grains  which  are  too 
old  will  not  germinate,  or  if  they  do  may  not  fertilize  the  ovule. 
(2)  The  vigor  of  the  tree  affects  the  viability  of  the  pollen. 
Healthy  trees  generally  produce  better  pollen  year  after  year 
than  do  sickly,  small,  stunted  ones.  (3)  The  age  of  trees  has 


POLLINATION  AND  FERTILIZATION  163 

some  effect  on  the  viability  and  abundance  of  pollen.     In 
some  cases  very  old  trees  produce  pollen  less  viable  than  do 
the  younger  individuals.     (4)  Weather  conditions  affect  the 
development  and  transporta- 
tion of  pollen.    Sunshiny  dry      c=^ 
weather  which  enables  bees  to        Q^        §ff$j& 
work  during  blossoming  time      <^      ^  °  ^ 
is  favorable.  Rain  at  the  time  K 

the  blossoms  open  is  unfa- 
vorable, because  it   not  Only    pIG.    104.— PoUen-grains    of    the    Drake 

soaks  the  dry  pollen  which  has      almond- 

been  shed  by  the  anthers  to  a  degree  that  injures  it,  but 
frequently  washes  it  away  so  that  it  is  lost.  Many  flowers 
have  ways  of  protecting  the  anthers  and  pollen  from  rains, 
such  as  by  drooping  so  that  the  rain-drops  will  be  shed,  or 
by  curling  up  the  stamens  so  that  the  anthers  are  drawn  into 
shelter.  Hot  dry  winds  are  unfavorable  on  account  of  their 
dessicating  nature.  Pollen-grains  from  most  kinds  of  fruit- 
trees,  however,  withstand  considerable  hot  weather  and 
sunshine.  Frost,  when  at  all  severe,  may  injure  the  anthers, 
but  in  most  cases  the  pistils  are  injured  before  the  anthers 
suffer. 

The  relation  of  the  pistil  to  pollination  and  fertilization 
is  important.  (1)  The  stigma  must  be  receptive.  This 
means  that  it  must  be  of  the  proper  age  and  condition  to  hold 
the  pollen-grain  and  to  furnish  the  necessary  stimulus  to 
cause  it  to  germinate.  The  stigmas  in  flowers  of  common 
fruit-trees  usually  remain  receptive  for  several  days.  Re- 
ceptive stigmas  are  neither  too  dry  nor  too  green.  They 
usually  take  on  a  peculiar  glistening  appearance  and  pro- 
duce a  sirupy  or  sticky  fluid  on  the  surface  which  causes  the 
pollen-grains  to  stick  tightly.  The  stigmatic  secretions 
seem  to  favor  the  germination  of  pollen-grains  of  certain 
varieties  and  to  prohibit  the  germination  of  those  of  other 
sorts,  but  the  chemical  action  involved  is  not  at  present  well 


164  HORTICULTURE  FOR  SCHOOLS 

understood.  (2)  The  style  must  be  of  the  proper  length  so 
that  the  tip  of  the  pollen-tube  will  just  reach  a  point  near  the 
micropyle  of  the  ovary  at  the  time  the  tube  is  ready  to  dis- 
charge the  pollen-cell  which  will  fertilize  the  ovule.  On  this 
account  pollen-grains  which  normally  produce  tubes  shorter 
than  the  length  of  the  style  cannot  successfully  fertilize  the 
ovule.  In  some  instances,  pollen-grains  normally  produce 
pollen-tubes  much  longer  than  the  style,  and  the  tip  of  the 
tube  grows  past  the  micropyle  before  being  ready  to  dis- 
charge the  cell  to  fertilize  the  egg-cell.  In  either  of  these 
cases,  fertilization  cannot  take  place.  (3)  The  tissue  of  the 
style  must  be  of  such  structure  that  the  pollen-tube  can 
penetrate  it.  Sometimes  the  style  possesses  a  stylar  canal, 
an  opening  down  which  the  pollen-tube  makes  its  way,  but 
often  the  tube  grows  down  through  the  tissues,  either  forcing 
its  way  between  the  cells,  or  actually  dissolving  some  of  them 
and  absorbing  the  dissolved  material  to  aid  in  its  own  growth. 
(4)  It  appears  that  the  cell  of  the  ovary  must  have  a  certain 
attraction  or  affinity  for  the  pollen-cell,  otherwise  fusion  of 
the  two  does  not  occur.  This  attraction  is  probably  chemical 
in  nature,  but  is  not  well  understood.  (5)  Weather, condi- 
tions may  be  favorable  or  unfavorable  in  relation  to  the  pistil. 
Sunshine  is  generally  favorable,  especially  by  rendering  it 
possible  for  bees  to  carry  pollen  from  flower  to  flower. 
Rainy  weather  is  unfavorable  to  mature  stigmas,  inasmuch  as 
the  water  washes  away  some  of  the  stigmatic  secretions. 
Dry  hot  winds  tend  to  cause  drying  of  the  stigmas. 

261.  Transportation  of  pollen  is  of  great  importance.  In 
some  of  the  lower  forms  of  plant  life,  the  little  sperm,  corre- 
sponding to  the  pollen-cell  of  higher  plants,  is  motile  and 
can  swim  through  films  of  moisture  to  the  egg-cell  of  the 
female  organ,  but  in  higher  forms  some  outside  agency  must 
be  depended  on  for  bringing  the  pollen  to  the  stigmas  of  the 
pistils.  There  are  three  main  transporting  agencies :  water, 
winds,  and  insects. 


POLLINATION  AND  FERTILIZATION  165 

1.  Water,  as  an  agent  in  carrying  pollen,  is  of  importance 
to  a  number  of  water  plants.    The  pollen  floats  on  the  water 
to  the  stigmas.     From  a  horticultural  point  of  view,  this 
method  of  transportation  is  of  little  importance. 

2.  Plants  depending  on  winds  for  pollination  are  said 
to  be  anemophilous.     A  considerable  amount  of  the  pollen 
carried  by  wind  is  scattered  and  wasted.     Consequently, 
anemophilous   plants   produce   enormous   quantities   of  it. 
The  pollen-grains  are  commonly  small  with  dry  surfaces, 
which   prevent   their   sticking   together.     In   many   cases, 
pollen-grains    possess    air    bladders    which    facilitate    wind 
transportation.    Various  modifications  of  the  usual  form  of 
pistil  are  frequently  present  in  cases  in  which  wind  is  de- 
pended on  to  carry  the  pollen.    An  example  of  this  is  shown 
in  the  many  branched  spreading  style  of  the  hazelnut  which 
is  especially  adapted  to  catch  and  hold  pollen-grains  floating 
in  the  air.    Many  of  the  nut-trees,  such  as  the  walnut,  butter- 
nut, and  pecan  depend  on  wind  pollination. 

3.  Insects  are  the  most  important   carriers  of  pollen. 
The  common  fruit-trees  depend  largely  on  bees  for  pollina- 
tion.   Such  plants  encourage  bees  to  visit  them  by  producing 
a  supply  of  nectar,  which  is  usually  secreted  by  nectar- 
glands  located  well  down  at  the  base  of  the  pistil  or  in  the 
lower  parts  of  the  flower,  so  that  the  bees,  in  order  to  obtain 
the  nectar  secreted  by  the  glands,  must  scramble  down  into 
the  flowers  and  get  well  dusted  with  pollen  in  doing  so. 
Flowers  depending  on  insects  for  pollination,  unlike  wind- 
pollinated   ones,   generally   produce   pollen-grains   of  good 
size,  comparatively  speaking,  and  frequently  the  outside  of 
the  grains  is  somewhat  sticky.    Such  pollen-grains  stick  to 
the  hairy  legs,  wings,  body,  and  head  of  the  bee.    In  going 
from  flower  to  flower,  the  bee  not  only  picks  up  pollen  but 
distributes  it,  for  as  it  goes  in  search  of  nectar  it  brushes 
some  of  the  pollen  against  the  stigmas,  where  numerous 
grains  stick,  and  pollination  is  accomplished.     Flowers  de- 


166 


HORTICULTURE  FOR  SCHOOLS 


pending  on  bees  for  pollination  are  said  to  be  entomophilous, 
and  attract  the  bees  by  their  odor  and  by  their  large  showy 
petals,1  while  wind-pollinated  flowers  are  commonly  small 
and  inconspicuous. 

262.  Ways  to  distinguish  good  from  poor  pollen. — It  is  of 
value  to  the  practical  fruit-grower  as 
well  as  to  the  scientific  worker  to  be 
able  to  distinguish  good  from  poor  pol- 
len without  actually  pollinating  blos- 
soms and  waiting  for  the  crop  to  set. 
Microscopic  examination  (Fig.  105)  is 


FIG.  105. — Showing  Van  Teighem  cell  with   pollen-grains   mounted   for   examination 
under  a  binocular  microscope. 

a  fairly  accurate  way  of  determining  whether  or  not  pollen  is 
viable.     Artificial  germination  is  a  sure  method.    To  deter- 

1  It  is  interesting  to  note  in  this  connection  that  flowers  supply  bees  not 
only  with  nectar  for  honey-making,  but  with  pollen  for  food  as  well.  If  bees 
are  watched  for  any  length  of  time  while  they  are  at  work  on  blossoms,  they 
will  be  seen  gathering  pollen  and  stuffing  it  in  curious  pocket-like  arrange- 
ments of  bristles  on  the  outside  parts  of  the  hind  legs.  The  bee-bread  found 
in  the  brood  combs  is  merely  this  pollen,  which  together  with  nectar  and 
honey  constitute  their  food.  These  industrious  insects  distribute  pollen  so 
economically  that  much  less  pollen  is  necessary  to  insure  pollination  and 
fertilization  in  entomophilous  plants  than  has  to  be  produced  by  anemoph- 
ilous  plants  for  the  same  purpose. 


POLLINATION  AND  FERTILIZATION 


167 


mine  which  are  the  good  pollen-grains  in  a  sample  by  use  of  the 
microscope,  it  is  necessary  first  of  all  to  know  what  is  the  nor- 
mal size  and  shape  of  the  grains.  The  normal  appearance  of 
the  grains  differs  in  various  species  and 
even  in  varieties.  An  examination  of 
the  pollen-grains  shown  in  the  photo- 
micrograph in  Fig.  104  will  make  this 
plain.  It  will  be  noticed  that  some  of 
the  grains  are  large  in  size,  others  are 
small,  and  some  are  medium  and  reg- 
ular in  outline.  Whenever  pollen- 
grains  depart  from  their  usual  size  and 
shape,  it  is  reasonably  certain  that 


FIG.  106. — Germination  of 
Black  Heart  sweet  cherry 
pollen.  A ,  grains  swelling ; 
B,  tube  starting;  C,  later 
stage  of  tube  growth. 


they  lack  viability  and  will  not  germinate.  Grains  smaller 
than  normal  or  very  much  larger  seldom  germinate.  Such 
grains  can  be  seen  among  the  normal  ones  in  the  illustration. 

A  microscopic  examination  of  pol- 
len-grains, then,  will  reveal  those 
that  are  "off-type"  and  will  not 
germinate. 

Although  it  is  fairly  certain  that 
the  grains  apparently  normal  will 
germinate,  this  is  not  always  the 
case.  On  this  account,  it  is  neces- 
sary to  have  accurate  methods  of 
testing  the  viability  of  pollen- 
grains.  This  is  done  by  placing 
them  in  artificial  media.  Pollen- 
grains  from  most  varieties  of 
fruit-trees  germinate  well  in  a 
solution  of  sugar  and  water  in  which  the  sugar  consti- 
tutes 12  per  cent  of  the  mixture.  That  the  pollen  may 
have  as  favorable  conditions  for  germinating  as  possible, 
it  is  mounted  in  the  culture  in  a  closed  glass  chamber 
known  as  a  Van  Teighem  cell,  one  of  which  is  shown 


Fia.  107. — Photomicrograph  of  Cal- 
ifornia almond  pollen-grains  ger- 
m  i  n  a  ti  n  g .  These  grains  were 
mounted  eight  hours  before  pho- 
tographing. Notice  the  length 
of  the  tubes  and  the  high  percent- 
age of  germination . 


168  HORTICULTURE  FOR  SCHOOLS 

in  Fig.  105.  This  cell  consists  of  a  ground  glass  ring  fastened 
on  a  microscopic  glass  slide  with  paraffine  or  vaseline.1  A 
glass  cover-slip  is  placed  on  the  top  of  the  ring  and  held  in 
place  by  a  little  vaseline.  A  few  drops  of  water  are  put  in 
the  bottom  of  the  cell  to  keep  the  chamber  moist.  The  pollen 
is  mounted  as  follows:  A  drop  of  the  germination  medium 
(sugar  solution  in  this  case)  is  applied  to  the  cover-slip  with 
a  glass  rod.  Pollen  is  dusted  upon  the  surface  of  the  drop, 
and  the  cover-slip  is  then  placed  on  the  vaselined  ring  so  that 
the  drop  hangs  downward,  and  is  within  the  moist  chamber. 
The  pollen  can  then  be  examined  with  a  microscope  at  any 
time.  (See  Fig.  105). 

After  the  grains  are  mounted,  they  begin  to  absorb  moisture 
through  their  coats  and  swell.  Soon  the  viable  grains  put 
forth  tubes,  which  continue  to  grow  until  they  attain  con- 
siderable length.  The  grains  of  pollen,  on  absorbing  mois- 
ture, first  change  their  shape  from  elliptical  to  round.  Next 
three  protuberances  appear.  From  one  of  the  protuberances 
the  pollen-tube  starts,  and  continues  to  grow  for  some  time 
as  is  shown  in  Figs.  106  and  107.  Many  kinds  of  pollen  do 
not  assume  this  triangular  shape  before  putting  forth  pollen- 
tubes.  Frequently  pollen-grains  have  certain  spots  or  modi- 
fied places  in  their  coats  for  the  emission  of  pollen-tubes.  By 
counting  the  germinated  and  non-germinated  grains  the  per- 
centage of  germination  can  be  obtained.  An  examination  of 
the  photomicrographs  will  show  that  a  high  percentage  of 
germination  may  be  expected  from  almond  pollen  (Fig.  107). 
The  percentage  of  germination  of  pollen  of  most  apple  varie- 
ties is  also  high.  On  the  other  hand,  Japanese  plum  pollen 
and  many  varieties  of  sweet  cherry  pollen  give  compar- 
atively low  tests.  The  hazelnut  pollen,  Fig.  103,  shows  a  very 

1  While  glass  rings,  which  may  be  obtained  from  dealers  in  optical  supplies, 
are  best  for  this  purpose,  fibre  rings  or  rings  of  sealing  wax  may  be  employed 
instead.  If  sealing  wax  is  used,  it  is  softened  in  a  flame  and  applied  to  the 
slide  in  the  form  of  a  circle,  after  which  the  top  is  leveled  off  with  a  sharp 
knife.  Hollow  ground-glass  slides  may  also  be  used. 


POLLINATION  AND  FERTILIZATION  169 

low  germination  test.  In  fact,  pollen  from  trees  and  shrubs 
which  depend  on  wind  for  distribution  is  seldom  high  in  ger- 
mination percentage. 

In  case  of  pollen  from  common  fruit-trees,  the  germination 
test  in  sugar  solutions  indicates  the  viability  of  the  pollen,  for 
grains  which  will  not  germinate  in  the  sugar  solutions  will 
not  germinate  and  fertilize  the  ovules  when  applied  to  the 
stigmas.  In  fact,  germination  media  are  known  with  which 
to  test  the  viability  of  any  sort  of  pollen,  although  no  one 
medium  has  been  found  which  works  equally  well  with  all 
varieties. 

263.  Viability  of  pollen  affected  by  various  factors. — In 
addition  to  the  factors  already  mentioned,  climate,  moisture 
supply,  physiological  conditions  of  the  tree,  and  earliness  of 
bloom  affect  the  viability  and  production  of  pollen.    How- 
ever, some  species  and  varieties  of  trees  produce  better  pollen 
than  others.    This  characteristic  seems  to  be  inherited  and 
remains  true  (but  is  varied  by  other  conditions)  from  year  to 
year.    The  Combination  plum  is  an  example  of  a  variety 
which  produces  pollen  of  poor  viability  and  also  in  very  scant 
amounts.    Its  pollen  is  not  sufficient  in  quantity  and  via- 
bility to  fertilize  other  trees  successfully.    In  general,  it  may 
be  said  that  some  species  of  trees  naturally  produce  pollen  of 
higher  viability  than  others,  and  may  also  yield  pollen  in 
larger  quantities.    The  apple  produces  pollen  in  abundance 
and  of  high  viability.    Varieties  of  trees  differ  in  the  amount 
of  pollen  borne.     Individual  trees  also  differ  in  this  regard. 
Many  hybrids,  that  is,  plants  resulting  from  the  crossing  of 
species,  produce  only  a  scant  quantity  of  pollen  which  is  fre- 
quently not  viable. 

264.  Inter-planting  for  pollination. — Inasmuch  as  pollina- 
tion bears  directly  on  fruit  production,  every  orchardist  is 
vitally  interested  in  planting  the  correct  mixture  of  varieties. 
Many  pollination  problems  are  still  unsolved.    Much  experi- 
menting is  being  done  to  determine  which  varieties  are 


170  HORTICULTURE  FOR  SCHOOLS 

self-fertile,  which  self-sterile,  and  which  inter-fertile,  and  to 
discover  what  crosses  produce  fruit  in  greatest  abundance. 
This  is  performed  by  artificially  pollinating  the  blossoms. 

265.  Artificial  pollination. — In  all  artificial  pollination,  the 
principles  taught  by  nature  are  utilized.     The  important 
points  to  bear  in  mind  are  to  secure  viable  pollen,  to  insure 
the  application  to  the  stigmas  of  the  kind  of  pollen  desired, 
to  exclude  from  the  stigmas  all  other  pollen,  and  to  keep  ac- 
curate records  of  the  results. 

The  operations  in  artificial  pollination  are  the  following: 

1.  Procuring,  treating,  and  keeping  the  pollen. 

2.  Preparing  the  flower  for  receiving  the  pollen,  and  tak- 
ing steps  to  prevent  pollination  by  other  means  than  those 
intended. 

3.  Applying  the  pollen  at  the  proper  time. 

4.  Keeping  the  records. 

266.  Procuring  the  pollen. — It  is  not  only  necessary  to 
secure  the  pollen,  but  it  is  convenient  and  sometimes  im- 
perative that  it  be  kept  for  a  short  time.    There  are  a  number 
of  good  methods  of  collecting  pollen.    In  the  case  of  plants 
which  are  ordinarily  wind-pollinated,  as  in  the  chestnut  and 
walnut,  all  that  is  necessary  is  to  procure  branches  on  which 
the  anthers  have  begun  to  dehisce  and  place  them  on  news- 
papers in  a  dry  room,  or  still  better  in  sunshine  under  a  glass 
cover  such  as  will  keep  out  wind  and  insects.    In  a  few  hours, 
or  a  day  or  two,  an  abundance  of  pollen  may  be  shaken  out 
on  the  newspapers.    If  the  pistillate  flowers  of  the  walnut  are 
to  be  pollinated  at  once,  it  is  only  necessary  to  shake  a  branch 
having  ripe  pollen  over  a  branch  of  the  pistillate  flowers. 
To  prevent  pollination  by  the  wind,  it  is  necessary  to  place 
paper  bags  over  the  portions  of  the  branches  to  be  pollinated 
sometime  before  the  stigmas  are  receptive.    The  bags  are  re- 
moved for  the  pollinating  and  are  replaced  again. 

In  the  case  of  ordinary  fruit-trees,  which  depend  on  insects 
for  pollination,  different  methods  are  necessary.    It  is  im- 


Plate  V. — Upper:  Irrigating  a  nursery  by  furrow  system. 
Lower:  Irrigating  orchard  by  basin  system. 


POLLINATION  AND  FERTILIZATION  171 

portant  to  remember  that  pollen  should  not  be  collected  from 
flowers  which  have  already  opened,  because  bees  working  on 
the  blossoms  will  have  brought  pollen  from  other  flowers  and 
it  will  be  mixed;  therefore,  in  selecting  blossoms  from  which 
pollen  is  to  be  obtained,  it  is  necessary  to  choose  flowers  not 
yet  opened.  It  is  best  to  select  buds  which  are  full-grown 
and  almost  ready  to  open,  but  whose  petals  as  yet  are  closed 
so  that  bees  have  not  entered.  These  buds  can  be  picked 
and  placed  in  paper  bags. 

One  method  of  obtaining  pollen  from  the  blossoms  is  to  pull 
off  the  corolla  and  place  the  flowers  on  newspapers  in  the  sun- 
light until  the  anthers  dehisce  and  shed  the  pollen.  A  much 
neater  way  is  to  scrape  or  cut  the  anthers  out  of  the  bud; 
in  this  way  they  can  be  obtained  nearly  free  from  other  ma- 
terial. The  anthers  are  placed  in  a  watch  glass  and  dried 
in  the  sun  until  the  pollen  is  shed.  It  is  best  to  put  the  watch 
glass  on  clean  sand  in  a  shallow  box,  which  should  be  covered 
with  a  pane  of  glass  to  prevent  the  entrance  of  insects  and 
dirt.  When  a  large  number  of  samples  of  pollen  are  to  be 
dried,  especially  constructed  glass  cases  are  generally  used. 
The  anthers  will  dry  in  bright  sunlight  in  a  few  hours,  or  at 
most  in  two  days. 

267.  Storing  the  pollen. — Pollen  prepared  as  indicated 
may  be  used  for  pollinating  purposes  at  once  or  may  be  stored 
and  kept  for  several  days  or  even  for  a  few  weeks.  Many 
kinds  of  pollen  may  be  kept  from  two  to  six  weeks  under 
favorable  conditions,  but  pollen  usually  deteriorates  after  a 
few  days,  and  the  longer  it  is  kept  the  lower  its  viability  be- 
comes. There  are,  however,  exceptions  to  this  rule;  for 
example,  pollen  from  the  date  palm  has  been  kept  viable 
for  years. 

In  storing  pollen  it  is  necessary  that  it  be  kept  dry  in  order 
to  prevent  molding.  A  convenient  way  is  to  brush  the  pollen 
and  anthers  from  the  watch  glass  into  a  glass  vial.  Ordina- 
rily it  is  well  to  cork  the  vials  with  cotton,  although  in  some. 


172  HORTICULTURE  FOR  SCHOOLS 

climates  it  is  considered  best  to  use  cork  for  the  purpose. 
Pollen  is  sometimes  stored  and  shipped  in  capsules  such  as 
are  employed  for  holding  quinine  and  other  drugs.  It  can 
also  be  kept  in  paper  bags  tied  securely. 

268.  Emasculating  the  flowers. — The  flowers  to  receive 
the  pollen  are  prepared  a  short  time  before  the  stigmas  are 
receptive.  In  order  to  prevent  self-pollination,  perfect  flowers, 
like  those  possessed  by  most  fruit-trees,  must  have  the  anthers 
removed  before  they  are  ripe.  This  process  is  known  as 
emasculation.  The  flowers  must  be  emasculated  before  the 
petals  open  in  order  to  prevent  the  carrying  of  pollen  to  the 
stigmas  by  insects,  and  as  soon  as  emasculated  should  be 
covered  with  paper  bags.  Flowers  may  be  emasculated  a  few 
days  before  they  would  naturally  open.  In  preparing  a 
twig  for  emasculation,  all  immature  buds  and  those  too  far 
advanced  should  be  removed. 

In  emasculating  flower-buds  of  the  common  stone-fruits 
(as  plum,  cherry),  enough  of  the  perianth  is  removed  to  take 
away  all  the  stamens.  A  study  of  the  flower  will  show  just 
how  much  of  the  calyx  it  is  necessary  to  remove  in  each 
variety.  There  are  several  ways  of  emasculating  flowers  of 
this  type.  One  way  is  to  cut  through  the  calyx  clear  around 
the  flower-bud  with  small  scissors,  leaving  the  pistil  intact. 
Another  method  is  to  make  the  cut  with  a  sharp  scalpel.  A 
better  and  faster  way  of  emasculating  flower-buds  of  this 
type  was  originated  by  E.  J.  Kraus  at  the  Oregon  Experiment 
Station.  This  consists  in  removing  the  proper  portion  of  the 
perianth  with  the  finger-nails  (See  Figs.  108-1 10) .  The  thumb 
and  second  finger  are  used  to  cut  through  the  side  of  the  bud 
as  illustrated  in  Fig.  109.  The  beginner  will  make  two  cuts 
with  the  nails,  one  on  either  side  of  the  bud,  and  at  the  second 
will  lift  the  loosened  perianth  over  the  top  of  the  pistil.  As 
one  becomes  more  expert,  he  will  make  but  one  cut  on  the  side 
of  the  bud,  tearing  around  the  bud  and  removing  the  perianth 
at  the  same  time.  By  using  this  method  it  is  possible  to 


POLLINATION  AND  FERTILIZATION  173 

emasculate  a  flower  with  one  motion.  As  many  as  1200  cherry 
blossoms  have  been  emasculated,  bagged,  and  labeled  by  one 
man  in  a  single  hour  by  this  method,  although  from  500  to 
800  blossoms  an  hour  are  nearer 
the  average  for  each  man. 

With  pome-fruits,  such  as  the 
apple,  pear,  and  quince,  the  calyx- 
tube  or  hollow  torus  develops  into 
a  portion  of  the  fruit.  When 
blossoms  of  the  pear  and  apple  are 
emasculated  by  the  method  just 
explained,  the  fruit  formed  will 
be  somewhat  deformed.  In  order 
to  prevent  fruit-deforming,  it  is  T 

FIG.    108. — Position  of  the  fingers 

the  custom  in  emasculating  flowers      for  emasculating. 
of  the  pome-fruits  to  leave  the  calyx,  merely  removing  the 
petals  and  anthers.    With  the  thumb  and  second  finger  the 

corolla  is  grasped,  a  little 
to  one  side  near  the  top,  and 
pulled  off.  Care  must  be 
taken  not  to  grasp  the 
pistil,  otherwise  its  top  will 
be  torn  off  when  the  petals 
are  removed.  The  flowers 
minus  the  corolla  will  be 
seen  to  have  the  stamens 
attached  to  the  rim  of  the 

FlSige??nIi£uttin8  through  the  calyx  with  the  calyx-cup.     The    stamens 

can    be    scraped    off    by 

running  the  points  of  curved  forceps  around  inside  the  rim 
of  the  cup.  If  any  of  the  anthers  fall  into  the  calyx-cup, 
they  can  be  blown  out  with  the  breath.  This  is  a  fairly 
rapid  method,  it  being  possible  to  emasculate,  bag,  and 
label  about  200  blossoms  an  hour. 

269.    Bagging  the  blossoms. — Although  bees  do  not  visit 


174  HORTICULTURE  FOR  SCHOOLS 

emasculated  flowers  to  the  extent  that  they  do  others,  it  is 
advisable  to  tie  a  bag  over  the  ends  of  twigs,  covering  the 
emasculated  blossoms.  The  bags,  in  addition  to  keeping 
insects  out,  also  serve  as  some  protection  to  the  pistils  from 

drying  winds.  Each  twig 
is  labeled  with  the  number 
of  blossoms  emasculated, 
the  date,  and  such  other 
information  as  may  be 
desired.  Fairly  durable 
tags  should  be  used. 

270.    Applying  the  pol- 

.  no.-The  perianth  removed.          len.— After  the  flowers  are 

bagged,  some  of  them  are 

examined  from  time  to  time,  and  when  the  stigmas 
are  bright,  shiny,  and  sticky,  they  are  ready  to  receive 
the  pollen.  The  pollen,  which  has  already  been  placed 
in  labeled  glass  vials  corked  with  cotton,  is  usually  applied  to 
the  stigma  with  a  small  camel's  hair  brush.  When  the  brush 
is  dipped  in  the  pollen,  it  will  hold  enough  for  pollinating  a 
large  number  of  stigmas,  and  all  that  is  necessary  is  to  touch 
each  stigma  with  it.  Examination  of  a  stigma  so  treated  will 
show  a  large  number  of  pollen-grains  on  its  glistening  surface. 
It  will  be  noticed  that  a  small  quantity  of  pollen  goes  a  long 
way  in  pollination.  If  the  pollen  in  the  vial  should  become 
scanty,  a  few  shakes  will  jar  more  out  of  the  anthers. 

271.  Labeling. — The  stigmas  may  be   counted  as  the 
pollen  is  applied  and  the  number,  together  with  other  infor- 
mation, written  on  a  tag  attached  to  the  twig.    The  record  of 
each  tag  may  be  kept  in  a  notebook  or  on  cards.    After  the 
pollen  is  applied,  the  bags  are  replaced,  and  later,  after  the 
fruit  is  set,  they  are  removed,  and  such  observations  as  are  nec- 
essaryiare  made  and  recorded.    The  tags  may  be  left  as  long  as 
desired,  and  observations  and  records  made  from  time  to  time. 

272.  Checks. — It  is  necessary  in  all  work  of  this  nature  to 


POLLINATION  AND  FERTILIZATION  175 

be  able  to  compare  the  set  of  fruit  obtained  as  the  result  of 
cross-pollination  with  that  secured  under  natural  conditions. 
Blossoms  are  counted  on  twigs  similar  to  those  cross-polli- 
nated and  the  twigs  are  tagged.  The  effect  of  cross-polli- 
nation can  then  be  estimated  correctly  by  comparing  the  set 
of  fruit  on  the  twigs  artificially  pollinated  with  that  on  twigs 
pollinated  under  natural  conditions. 

273.  Choosing  varieties  for  pollination  purposes. — By 
extensive  experimenting,  the  kinds  of  pollen  can  be  found 
which  give  the  best  set  of  fruit  for  any  particular  variety. 
In  order  that  an  abundance  of  fruit  may  set,  the  grower  must 
in  many  cases  inter-plant  with  trees  of  the  proper  variety  for 
supplying  suitable  pollen.  It  is  important  to  know  that  some 
varieties  are  inter-sterile,  that  is,  will  not  set  fruit  when  cross- 
pollinated.  For  example,  the  Bing  and  Napoleon  (Royal 
Ann)  sweet  cherries  are  inter-sterile.  The  Bing  will  not  set 
fruit  when  pollinated  with  the  Napoleon  pollen,  and  neither 
will  the  Napoleon  set  fruit  when  pollinated  with  Bing  pollen. 
In  like  manner,  Nonpareil  and  IXL.  almond  varieties  are 
inter-sterile.1  On  the  other  hand,  some  varieties  are  inter- 
fertile,  that  is,  their  pollen  will  fertilize  each  other.  The 
Napoleon  and  Black  Republican  varieties  of  sweet  cherries 
are  examples. 

Some  fruit-trees  are  self -fertile,  ,or  will  set  fruit  well  even 
when  self -pollinated.  Most  peach  trees  are  self -fertile.  In 
setting  out  an  orchard,  in  addition  to  selecting  good  com- 
mercial varieties,  the  grower  must  select  kinds  which  are 
either  self-  or  inter-fertile.  In  the  past,  many  growers  have 
planted  large  blocks  of  a  single  desirable  commercial  variety 
of  fruit,  only  to  learn  after  a  number  of  years  that  the  sort 
would  not  produce  well  because  it  was  self -sterile.  Indeed, 
it  is  not  sufficient  to  know  that  a  variety  is  generally  self- 
sterile  or  self -fertile,  but  the  grower  should  know  the  facts 
with  reference  to  his  own  section  of  the  country.  For  ex- 

» Bull.  306,  Calif.  Exp.  Sta. 


176  HORTICULTURE  FOR  SCHOOLS 

ample,  the  Bartlett  pear  is  self-sterile  in  the  East,  but  is 
self-fertile  in  the  Pacific  Coast  states,  although  cross-polli- 
nation may  increase  the  crop  even  in  the  Pacific  states. 

274.  Requisites  of  good  pollinizer. — In  choosing  trees  for 
pollinating  any  variety,  several  requisites  of  good  pollinizers 
should  be  carefully  considered. 

1.  Varieties  must  not  only  be  able  to  pollinate  each  other, 
but  must  produce  pollen  at  the  time  it  is  needed  by  the  other 
trees;  that  is,  they  must  bloom  at  approximately  the  same 
time.     If  one  variety  blooms  early  and  the  other  late,  the 
pistils  of  the  early-blooming  sort  will  be  past  the  receptive 
stage  when  pollen  of  the  late-blooming  kind  is  ready,  and 
the  pistils  of  the  late-blooming  variety  will  not  be  receptive 
until  sometime  after  the  pollen  from  the  early-blooming 
tree  has  been  shed.    For  example,  it  would  be  of  no  use  to 
inter-plant  Chapman  and  Napoleon  sweet  cherries  for  inter- 
pollination,  because  the  Napoleon  does  not  blossom  until  the 
Chapman  has  finished  its  blooming  period. 

2.  Any  variety  intended  for  pollinizing  another  kind  must 
produce   viable   pollen   in  abundance.     The   Combination 
Japanese  plum  has  already  been  mentioned  as  being  unsuit- 
able for  pollination  purposes,  as  it  produces  pollen  very 
sparingly. 

3.  Late-blooming  varieties  escape  frost  more  often  than 
early-blooming  ones.    This  is  not  only  the  case  with  fruit 
that  has  already  set,  but  is  true  also  of  the  flowers  just  after 
they  have  been  pollinated,  and  before  the  pollen-tube  has 
reached  the  ovary.    Some  species  of  early  bloomers  will  stand 
frost  better  than  others.     Japanese   plums,    for   example, 
will  stand  more  frost  than  apricots,  even  in  case  of  those 
varieties  blooming  at  the  same  time. 

4.  Varieties  which  are  good  from  a  commercial  stand- 
point should  be  chosen  for  inter-pollination.    For  example, 
if  it  is  desired  to  plant  varieties  of  pears  for  pollinating  the 
Bartlett,  a  kind  should  be  chosen  which  will  pollinate  the 


POLLINATION  AND   FERTILIZATION  177 

Bartlett  and  also  produce  a  good  crop  itself,  as  a  result  of 
fertilization  either  from  Bartlett  pollen  or  from  its  own  pollen. 
5.  In  some  cases  it  may  be  desired  to  plant  mostly  one 
variety  and  just  enough  of  the  pollinizer  to  insure  produc- 
tion of  the  desirable  fruit.  As  an  illustration,  suppose  that 
one  wishes  to  grow  Warfield  strawberries  for  market.  As  the 
Warfield  bears  pistillate  flowers  only,  it  will  be  necessary  to 
plant  rows  of  some  variety  having  stamens  to  fertilize  it. 
Suppose  that  the  Lovett  is  chosen  for  this  purpose.  As  the 
Lovett  bears  perfect  flowers  and  is  self -fertile,  it  will  bear 
fruit  without  being  cross-pollinated,  and  will  at  the  same 
time  furnish  pollen  for  the  Warfield.  Although  the  Lovett  is 
a  good  berry,  it  does  not  stand  shipping  so  well  as  the  War- 
field  and  the  grower  will  prefer  the  Warfield.  On  account  of 
desiring  as  large  a  proportion  of  Warfield  berries  as  possible, 
instead  of  planting  every  other  row  of  the  Warfield  patch 
with  the  Lovett,  the  grower  will  plant  much  less,  probably 
every  third  or  fourth  row  with  the  Lovett,  an  arrangement 
which  would  furnish  an  ample  number  of  plants  to  pollinate 
the  Warfield.  The  grower  will  then  have  a  good  combination 
for  the  purpose  intended. 

If  trees  do  not  bear  well  and  the  reason  is  not  apparent,  the 
orchardist  should  study  them  as  to  quantity  and  viability 
of  pollen,  self-sterility  (or  inter-sterility  and  relative  bloom- 
ing dates  if  he  has  more  than  one  variety)  and,  in  general, 
as  to  the  availability  of  suitable  pollen  for  fertilizing  the 
blossoms.  Owing  to  variations  in  the  behavior  of  varieties 
in  different  sections  of  the  country,  the  grower  should  obtain 
information  from  the  nearest  experiment  station  as  to  the 
desirable  combinations  tp  plant,  insofar  as  such  information 
can  be  given. 

EXERCISES 

EXERCISE  I. — Study  of  flower  structure. 

Materials. — Blossoms  of  fruit-trees;    sharp  knife  or  scalpel;  mag- 
nifying glass. 


178  HORTICULTURE  FOR  SCHOOLS 

Procedure. — Study  various  flowers  for  the  purpose  of  becoming 
familiar  with  their  structure.  Make  diagrams  showing  the  different 
parts.  Label  all  parts.  Compare  flowers  of  species  of  fruit-trees,  note 
any  differences  in  their  structure. 

EXERCISE  II. — Study  of  pollen-grains. 

Materials. — Flower-buds  from  various  fruit-trees;  watch  glasses  or 
petri  dishes  in  which  to  dry  anthers;  microscope;  glass  slides  and 
cover-slips. 

Procedure. — Collect  some  flower-buds,  remove  the  anthers  and  dry 
according  to  methods  described  in  this  chapter.  Examine  the  grains 
of  various  pollens  by  use  of  the  microscope.  Sketch  typical  grains, 
making  drawings  large  enough  to  show  their  shape.  Store  some  pollen 
for  future  use  according  to  methods  given  in  this  chapter. 

EXERCISE  III. — Germination  of  pollen-grains  and  the  study  of  their 
tubes. 

Materials. — Van  Teighem  cells,  or  materials  for  making  the  same 
(see  paragraph  262) ;  sugar  solutions;  pollen-grains. 

Procedure. — Mount  some  pollen-grains  in  hanging-drop  cultures  as 
described  in  the  text.  Examine  them  from  time  to  time  in  order  to 
observe  the  pollen-tubes  of  different  lengths.  Make  drawings  showing 
some  of  the  germinated  grains  with  their  pollen-tubes.  Notice  the 
comparative  size  of  grains,  diameter  and  lengths  of  the  tubes,  and  rates 
of  growth  of  the  tubes  in  different  varieties  of  pollen.  The  following 
are  a  few  suggestive  species  of  orchard  trees  and  bush-fruits  from  which 
pollen  may  be  obtained  at  the  proper  time:  almond,  apple,  apricot, 
European  plum,  Japanese  plum,  peach,  pear,  walnut,  grape,  raspberry, 
blackberry,  date  palm. 

EXERCISE  IV. — Practice  in  emasculation  of  flowers. 

Materials. — Fruit-trees  in  bloom. 

Procedure. — Emasculate  some  blossoms  when  they  have  reached  the 
proper  stage  according  to  methods  described  in  this  chapter.  Apply 
some  pollen  to  the  stigmas.  Notice  how  tightly  the  pollen  sticks. 

EXERCISE  V. — Exercise  to  show  the  effects  of  self-pollination  versus 
cross-pollination  on  the  setting  of  fruit. 

Materials. — Fruit-trees  in  bloom;  viable  pollen  of  different  varieties 
of  the  species  emasculated;  tags,  paper-bags,  and  string. 

Procedure. — Select  a  variety,  carefully  emasculate,  and  bag  the 
blossoms  on  a  number  of  branches.  When  the  stigmas  are  receptive, 


POLLINATION  AND  FERTILIZATION  179 

pollinate  a  number  of  flowers  with  pollen  from  the  same  variety.  In 
the  same  way,  pollinate  stigmas  on  some  branches  with  pollen  obtained 
from  other  varieties.  Rebag  and  label  the  twigs.  Make  records  and 
notes  carefully.  Later  in  the  season  obtain  the  percentages  of  fruit 
set  in  the  different  cases.  From  the  results  determine  what  pollen 
produced  the  best  set  of  fruit  and  what  varieties  would  appear  to  do 
best  when  inter-planted. 

EXERCISE  VI. — Blooming  periods. 

Materials. — Various  kinds  of  orchard  trees  in  spring  time. 

Procedure. — Keep  blossoming  records  in  a  tabulated  form  for 
different  varieties  of  fruits  in  your  locality.  Record  the  following  facts 
for  each  variety: 

a.  Date  when  buds  show  first  signs  of  swelling. 

b.  Date  when  color  of  petals  shows  distinctly  in  bud. 

c.  Date  when  flower-buds  are  right  for  emasculating  (just  before 
petals  open). 

d.  Date  when  flowers  are  wide  open,  that  is,  when  tree  is  in  full 
bloom. 

e.  Date  when  most  of  the  petals  fall. 

By  some  kind  of  a  diagram  indicate  the  blooming  periods  of  the 
different  varieties  so  that  it  may  be  seen  at  a  glance  just  how  far  the 
varieties  overlap  so  as  to  be  useful  for  inter-planting  for  purposes  of 
pollination,  assuming  that  the  varieties  are  inter-fertile. 

EXERCISE  VII. — Project  exercise.  If  the  student  has  access  to  a 
tree  of  relatively  poor  bearing  qualities,  he  may  make  it  his  study  to 
ascertain:  (a)  whether  or  not  the  tree  produces  viable  pollen;  (b)  how 
the  viability  of  its  pollen  compares  with  that  of  good  bearers  of  the 
same  variety;  (c)  whether  or  not  the  tree  is  self -sterile;  (d)  whether 
there  is  any  other  variety  suitable  and  near  enough  to  pollinate  it; 
(e)  whether  or  not  pollination  by  any  other  variety  increases  its  fruit- 
bearing  capacity. 

If  there  is  some  obvious  reason  why  the  tree  is  a  poor  bearer,  such  as 
poor  location,  presence  of  insects  or  blight,  or  lack  of  care,  such  an 
exercise  would  be  wasted.  Otherwise  its  results,  if  carefully  obtained, 
may  prove  of  great  interest  and  value. 


CHAPTER  XIII 
DECIDUOUS  FRUITS 

TREES  that  shed  all  their  leaves  at  approximately  the  same 
time  are  deciduous,  while  those  that  retain  their  foliage  the 
year  round  and  shed  their  leaves  gradually  are  said  to  be 
evergreen. 

Many  of  the  deciduous  fruit-trees  belong  to  that  botanical 
group  known  as  the  Rose  family.  The  Rosacese  is  divided 
into  five  or  six  sub-families  or  tribes,  each  of  which  contains 
some  of  the  best  known  fruits  and  flowers.  The  Pome  tribe 
includes  the  apple,  pear,  quince,  and  hawthorn.  The  Bramble 
tribe  contains  the  blackberry,  raspberry,  and  dewberry.  The 
Drupe  tribe  is  represented  by  the  peach,  plum,  nectarine, 
cherry,  and  apricot.  The  strawberry  belongs  to  another 
group  known  as  the  Potentilla  tribe.  The  Rose  tribe  in- 
cludes the  familiar  ornamental  plants  of  the  same  name. 

275.  The  apple. — The  history  of  the  apple  is  obscure. 
It  probably  originated  in  southwestern  Asia,  but  apples  are 
found  wild  in  many  parts  of  the  world.  There  are  several  wild 
species  in  Europe  and  Asia.  According  to  Bailey,  at  least 
five  types  are  native  to  the  United  States :  the  Oregon  crab- 
apple,  from  Alaska  to  northern  California ;  two  species  in  the 
Mississippi  Valley,  the  Garland  crab  in  the  North  (which 
may  represent  more  than  one  species)  and  the  narrow-leaved 
crab  in  the  South;  the  Prairie  States  crab,  wild  in  Minnesota, 
Wisconsin,  Illinois,  Iowa,  Missouri,  and  Kansas;  and  the 
Soulard  crab,  which  is  sometimes  considered  a  cultivated 
variety,  but  which  Bailey  lists  as  occurring  in  a  wild  state 
from  Minnesota  to  Texas. 

180 


DECIDUOUS  FRUITS  181 

Pliny  mentions  the  apple  in  his  writings.  A  score  of  varie- 
ties were  known  at  that  time,  but  they  were,  of  course,  inferior 
to  the  modern  apple.  There  is  abundant  evidence  that  the 
fruit  was  brought  to  Great  Britain  from  the  mainland  at  the 
time  of  the  Roman  conquest,  and  in  1688  Ray  enumerated 
seventy-eight  varieties  in  cultivation.1 

The  geographical  distribution  of  the  apple  is  greater  than 
that  of  any  other  fruit,  but  the  United  States  and  Canada 
lead  the  world  in  its  production.  In  the  United  States  the 
eight  leading  apple-producing  states,  arranged  according  to 
acreage  are:  New  York,  Washington,  Virginia,  Pennsyl- 
vania, Ohio,  Michigan,  Missouri,  Illinois,  Arkansas,  and 
Oregon.  The  warm  Gulf  section  and  a  portion  of  the 
western  prairies  do  not  yield  apples  on  a  commercial  scale. 
In  Canada,  the  region  beginning  with  Nova  Scotia  and 
extending  westward  along  the  St.  Lawrence  River  and  the 
Great  Lakes  has  long  been  famous  for  its  apples.  The  follow- 
ing provinces  of  Canada  grow  apples  commercially :  Ontario, 
Nova  Scotia,  Quebec,  British  Columbia,  New  Brunswick, 
Prince  Edward  Island,  and  Manitoba.  Alberta  and  Sas- 
katchewan also  produce  some  apples. 

Apples  grow  on  almost  any  type  of  soil,  but  a  deep,  fertile, 
well-drained  soil  is  best.  The  apple  does  better  on  rather 
heavy  loam  than  it  does  on  sand.  The  tree  will  tolerate  a 
considerable  amount  of  gravel,  if  the  soil  itself  is  of  good 
fertility. 

In  his  Standard  Cyclopedia  of  Horticulture,  Bailey  has 
the  following  to  say  concerning  varieties:  "Each  great  geo- 
graphical area  has  varieties  that  are  particularly  adapted  to 
it.  In  the  northern  .Mississippi  Valley,  there  are  few  of  the 
eastern-states  apples  that  thrive.  Varieties  have  been  intro- 
duced from  Russia  with  the  expectation  that  they  will  be 
adapted  to  the  region;  but  more  is  to  be  expected  of  their 
progeny  than  of  themselves.  Varieties  of  local  origin,  coming 

1  Encyclopaedia  Britannica. 


182  HORTICULTURE  FOR  SCHOOLS 

from  various  stem  types,  are  now  providing  that  region  with 
satisfactory  apples.  In  the  selection  of  varieties,  one  should 
be  guided  by  this  adaptation  to  the  region,  and  by  the  pur- 
pose for  which  the  fruit  is  designed  to  be  grown.  Consult  the 
recommended  lists  of  the  state  horticultural  societies;  ask 
persons  who  have  had  experience  in  the  given  region;  write 
to  the  experiment  station;  enquire  at  the  market s." 

The  most  common  disease  of  the  apple  is  the  apple-scab, 
which  is  controlled  by  spraying  with  bordeaux  mixture.  The 
bulletins  of  the  several  states  should  be  consulted  as  to  time 
and  method  of  applying  the  spray  for  most  efficient  results. 
Lime-sulfur  spray  is  another  remedy  much  used  at  the  present 
time  for  the  disease. 

Of  all  the  insects  the  apple-grower  must  combat,  the  codlin- 
moth  is  undoubtedly  the  worst.  The  method  of  control  is  dis- 
cussed in  Chapter  XVI.  It  should  be  noted  that  one  spraying 
is  not  sufficient,  as  there  are  several  broods  each  year;  there- 
fore, the  process  must  be  repeated  at  definite  intervals,  ac- 
cording to  the  experience  of  each  locality  in  dealing  with  the 
insect.  The  apple  aphis  is  controlled  by  nicotine  sulfate 
sprays.  The  eggs  may  be  destroyed  in  the  winter  by  the 
application  of  kerosene  emulsion.  Nicotine  sulfate  is  used 
as  a  spray  for  woolly  aphis  also.  Another  method  of  dealing 
with  the  woolly  aphis  on  the  roots  is  to  scrape  off  a  few  inches 
of  top  soil  and  apply  kerosene  emulsion  or  tobacco  mixtures, 
allowing  it  to  soak  through  the  soil  to  the  roots.  Northern 
Spy  apple  stock  is  most  resistant  to  woolly  aphis. 

The  apple  is  propagated  by  grafting  and  sometimes  by 
budding. 

276.  The  pear. — It  is  probable  that  at  one  time  the  pear 
grew  wild  over  southwestern  Europe  from  the  Caspian  Sea 
to  the  Atlantic  Ocean.  When  it  came  under  cultivation,  or 
how,  it  is  impossible  to  say.  The  fruit  has  been  domesticated 
for  a  long  time,  for  it  was  well  known  to  the  early  Greek 
writers,  and  there  are  records  of  it  among  the  Romans.  Over 


DECIDUOUS  FRUITS  183 

sixty  varieties  of  pears  were  listed  for  sale  in  the  catalogues 
of  London  nurserymen  early  in  the  seventeenth  century. 
Pear  culture  was  developed  to  a  remarkable  extent  in  France. 
According  to  Peter  Henderson,  a  single  nursery  in  France 
carried  a  stock  of  3600  varieties. 

As  the  pear  seems  to  be  somewhat  less  troubled  by  its 
chief  enemy,  the  blight,  in  regions  near  large  bodies  of  water 
than  in  the  dry  interior  parts  of  the  country,  very  successful 
pear  sections  are  those  south  of  the  Great  Lakes  region  and 
east  to  the  Atlantic,  and  in  the  Pacific  states.  California, 
New  York,  Michigan,  Oregon,  and  New  Jersey  have  about 
half  the  pear  acreage  in  the  United  States.  Eastern 
Maryland,  Delaware,  the  region  along  the  southern  part  of 
Lake  Michigan,  the  Yakima  Valley  of  Washington,  and  the 
Rogue  River  Valley  of  Oregon  are  well  known  pear-producing 
sections.  Pears  are  not  grown  to  nearly  as  great  an  extent 
in  Canada  as  are  apples.  They  are  raised  for  the  most  part 
in  the  Ontario  region  west  of  Lake  Ontario,  in  Nova  Scotia, 
in  British  Columbia,  and  to  a  slight  extent  on  Prince  Edward 
Island. 

The  pear  thrives  on  heavy  soils  and  will  withstand  more 
water  than  other  fruit-trees.  Pears  will  not  tolerate  a  light 
sandy  soil.  Care  must  be  exercised  in  fertilizing  the  soil,  in 
irrigating,  and  in  cultivating  the  trees.  The  organism  caus- 
ing the  blight  usually  enters  through  the  flowers,  but  it  may 
also  gain  access  through  the  soft  moist  tissues  of  the  rapidly 
growing  tips.  Any  type  of  fertilization  or  cultural  methods 
causing  a  rapid  and  " sappy"  growth  should  be  avoided, 
especially  in  seasons  when  the  blight  is  prevalent. 

With  the  exception  of  a  few  varieties,  pears  are  picked 
green  and  allowed  to  ripen  in  storage,  as  the  flavor  is  better 
than  if  they  are  allowed  to  ripen  on  the  tree. 

Some  varieties  of  pears  in  certain  localities  are  self-sterile 
and  require  the  planting  of  other  kinds  with  them  for  pollina- 
tion purposes. 


184  HORTICULTURE  FOR  SCHOOLS 

277.  The  quince  (Plate  VI)  tree  is  shallow-rooted  and  can 
live  on  low  wet  land,  although  it  thrives  much  better  on  well- 
drained  deep  soils.  The  fruit  is  used  for  making  jams,  preserves, 
and  jellies.  It  is  much  prized  in  preserves  when  mixed  with  other 
fruits,  owing  to  the  distinctive  flavor  which  it  imparts.    The 
quince  tree  is  hardy,  grows  with  little  care,  and  produces  well. 

278.  The  peach. — It  now  seems  certain  that  the  peach 
came  originally  from  China.    From  China  it  apparently  was 
carried  to  India  and  Persia  where  it  came  into  extensive  use; 
and  from  here  it  went  to  Greece  and  Italy.    After  its  intro- 
duction into  Greece  about  2000  years  ago,  reference  to  it 
from  time  to  time  makes  it  possible  to  trace  its  progress  from 
Italy  into  France  and  from  France  to  Belgium,  Holland, 
Spain,  and  England.    Following  the  discovery  of  America, 
the  fruit  was  introduced  into  Mexico  and  South  America  and 
it  is  from  the  varieties  that  developed  there  that  the  group  of 
so-called  Indian  peaches  has  arisen. 

In  the  United  States,  the  peach  takes  high  rank  commer- 
cially, being  second  to  the  apple  alone  among  orchard  fruits. 
The  regions  of  the  most  intense  winter  cold  are  unsuitable 
for  peach  culture.  According  to  the  United  States  Census 
reports,  over  75  per  cent  of  the  peaches  produced  in  the  United 
States  are  grown  south  of  the  Ohio  and  Missouri  rivers  and  in 
California.  North  of  the  Ohio  and  Missouri  rivers  the  climate 
is  too  severe  for  their  production.  The  climate,  however,  is 
milder  along  the  shores  of  the  Great  Lakes  and  peaches  are 
grown  successfully  to  the  south  and  east  of  them.  In  Canada 
peaches  are  produced  commercially  in  the  Niagara  Peninsula 
and  in  other  parts  of  Ontario  lying  along  the  northern  shore 
of  Lake  Erie,  in  western  Nova  Scotia,  and  in  the  lower  Oka- 
nagan  Valley  in  British  Columbia. 

The  peach,  when  grown  on  its  own  roots,  is  adapted  to  a 
light  sandy  soil,  and  does  not  thrive  on  heavy  clay  land.  In 
order  to  adapt  it  to  heavy  soils,  it  is  sometimes  grafted  on 
Myrobalan  or  other  plum  roots. 


DECIDUOUS  FRUITS  185 

Yellows  and  rosette  are  serious  diseases  of  the  peach  for 
which  no  remedy  is  known.  Curl-leaf  is  a  fungus  controllable 
by  the  application  of  bordeaux  mixture  or  lime-sulfur  solu- 
tion very  early  in  the  spring  ten  to  fifteen  days  before  the 
bursting  of  the  buds. 

The  three  most  common  insect  enemies  are  the  peach-tree 
borer,  the  San  Jose  scale,  and  the  curculio.  The  first  is  the 
most  difficult  to  eradicate.  The  scale  is  controlled  by  spray- 
ing, and  the  curculio  by  clean  cultivation,  collecting  and 
destroying  the  insects,  and  by  spraying.  (See  Chapter  XVI.) 

Choice  of  varieties  of  peaches  depends  primarily  on  market 
and  climate;  quality  of  fruit  and  resistance  of  the  tree  to 
disease  are  also  factors  of.  importance.  In  most  localities 
growers  select  from  three  to  five  varieties  that  are  suited  to 
local  needs,  and  whose  time  of  ripening  is  such  that  the  work 
of  picking  is  distributed  through  as  long  a  period  as  possible. 
This  enables  the  grower  to  handle  the  picking  problem  with 
a  minimum  loss  of  fruit.  Most  peach  varieties  are  self -fertile. 

The  peach  is  propagated  almost  entirely  by  budding. 

279.  The  nectarine  is  really  a  smooth-skinned  peach. 
Many  varieties  have  long  been  grown  in  Asia.    Nectarines 
have  been  known  to  arise  from  peach  trees  as  bud-sports. 
It  is  a  fine  fruit  but  is  not  grown  commercially  to  the  extent 
it  deserves.    Cultural  methods  are  the  same  as  for  the  peach. 

280.  The  apricot  is  probably  a  native  of  China  or  Japan. 
The  Persians  named  this  fruit  the  "Seed  of  the  sun."    The 
apricot  was  introduced  into  England  in  the  early  part  of  the 
sixteenth  century.    It  is  a  popular  garden  fruit  in  some  special 
locations  in  eastern  United  States,  and  even  in  the  milder 
parts  of  the  Canadian  lake  region.    Owing  to  its  early  blos- 
soming habit,  spring  frosts  limit  its  production  to  specially 
favored  localities.    California  produces  practically  the  entire 
commercial  apricot  crop  of  North  America. 

The  fruit  resembles  a  small  peach  somewhat  and  has  a  pit 
similar  in  shape  to  that  of  the  wild  plum.  The  apricot  is 


186  HORTICULTURE  FOR  SCHOOLS 

excellent  when  ripe,  and  has  a  peculiar  flavor  of  its  own.  It 
makes  a  fine  dried  product  which  is  free  from  the  leathery 
skin  and  heavy  pubescence  characteristic  of  the  dried  peach. 
The  properly  dried  apricot  maintains  its  distinctive  flavor. 

The  tree,  with  its  reddish-brown  bark  and  heavy  foliage  of 
deep  green  heart-shaped  leaves,  is  one  of  the  most  beautiful  in 
the  orchard.  It  is  a  strong  vigorous  grower.  When  budded  on 
peach  root,  the  apricot  thrives  on  light  deep  loams.  For  the 
heavier  loams  it  should  be  budded  on  apricot  stock.  Attempts 
have  been  made  with  various  degrees  of  success  to  grow  the 
apricot  on  heavy  soils  by  budding  it  on  Myrobalan  or  other 
plum  stock. 

Gum  disease,  brown-rot,  and  shot-hole  fungus  are  common 
diseases  of  the  apricot. 

281.  Plums  and  prunes. — The  plum  is  spoken  of  by  Pliny 
in  such  a  way  as  to  indicate  that,  at  the  time  he  wrote,  it  was 
a  comparatively  new  fruit.  It  had  probably  been  brought 
to  Greece  and  Rome  a  short  time  before  by  some  of  the  raiding 
hordes  from  the  region  of  the  Caucasus  and  the  Caspian;  for 
there  is  evidence  to  support  the  theory  that  it  first  became 
domesticated  somewhere  in  this  region.  In  America,  the 
plum  had  begun  to  assume  some  importance  as  a  cultivated 
fruit  by  the  beginning  of  the  nineteenth  century.  Three 
types  of  plums,  the  European,  the  Japanese,  and  the  native, 
are  grown  in  North  America. 

The  Japanese  plums  are  native  of  China.  This  species  was 
introduced  into  America  from  Japan  about  1870,  and  began 
to  attract  attention  a  few  years  later.  By  1880  it  was  widely 
propagated.  While  the  tree  is  adapted  to  a  wide  range  of 
conditions,  its  early  blooming  habit  renders  the  blossoms 
liable  to  frost-injury.  On  this  account  it  cannot  succeed  in 
all  sections  where  the  European  plum  thrives,  but  owing  to 
its  large  attractive  fruit,  its  resistance  to  plant  disease,  and 
its  early-bearing  habit,  it  is  grown  extensively  in  North 
America. 


DECIDUOUS  FRUITS  187 

In  addition  to  the  European  and  Japanese  plums,  North 
America  has  many  native  species.1 

Plums  are  distributed  widely  over  the  United  States. 
According  to  the  last  census,  over  one-third  of  the  acreage 
in  plums  is  in  California,  the  greatest  producing  section  in 
the  world  being  the  Santa  Clara  Valley  which  yields  about 
one-fourth  of  the  plums  and  prunes  grown  in  the  United 
States.  Oregon  produces  large  quantities  of  plums  and 
prunes  and  Washington  a  smaller  amount. 

Canada  grows  plums  over  a  wide  area.  W.  T.  Macoun 
says:  "The  plum  has  not  been  as  profitable  to  grow  in  Can- 
ada as  some  other  fruits,  but  with  a  careful  selection  of  varie- 
ties and  good  care  it  will  be  found  to  give  fairly  good  returns. 
In  those  parts  of  Canada  where  European  plums  do  not 
succeed,  the  improved  native  and  American  varieties  have  been 
found  very  profitable.  Some  of  these  ripen  before  the  Euro- 
pean plums  come  on  the  market  and  they  sell  at  high  prices/'2 

European  plums  succeed  well  in  Prince  Edward  Island, 
Nova  Scotia,  the  south  shore  of  the  St.  Lawrence  River,  in 
Quebec,  British  Columbia,  and  Ontario.  Japanese  varieties 
are  grown  in  the  south  coastal  region  of  Nova  Scotia,  western 
Ontario,  and  the  milder  parts  of  British  Columbia. 

It  must  be  kept  in  mind  that  when  the  word  "plum"  has 
been  used,  the  "prune"  is  understood  as  being  included,  the 
prune  being  a  plum  that  contains  sufficient  sugar  to  enable 
it  to  be  dried  without  removal  of  the  pit.  The  two  fruits  are 
alike  in  every  other  respect.  An  analysis  of  the  prune  from 
the  standpoint  of  food  value  shows  that  it  is  in  a  class  quite 
by  itself.  The  dried  article  contains  2.1  per  cent  protein  and 
73.37  carbohydrate;  and  there  are  records  of  prunes,  the 
dried  edible  portion  of  which  analyzed  50  per  cent  sugar. 
It  is,  therefore,  high  in  food  value,  yielding  nutriment  in  an 
easily  digested  form  at  a  nominal  cost. 

1  Bailey,  Evolution  of  Our  Native  Fruits. 

*Bull.  43,  Dominion  of  Canada  Dept.  Agric.  Exp.  Farms,  1918. 


188  HORTICULTURE  FOR  SCHOOLS 

Prunes  are  usually  picked  from  the  ground  rather  than 
from  the  trees;  for  it  has  been  found  that  they  contain  a 
higher  proportion  of  solids  if  allowed  to  remain  on  the  tree 
as  long  as  possible.  The  drying  process  is  then  completed  in 
one  of  three  ways :  In  Europe,  the  fruit  is  half  baked  in  ovens 
and  drying  is  then  finished  in  the  open  air.  In  California 
this  is  usually  done  out-of-doors,  in  the  sun.  In  the  Pacific 
Northwest,  where  the  air  is  more  humid,  special  buildings 
erected  for  the  purpose,  called  evaporators,  are  utilized. 
Each  method  has  some  points  in  its  favor.  The  European 
system  is  said  to  impart  to  the  fruit  an  especially  desirable 
flavor,  but  the  product  is  unsightly,  and  therefore  lacks  the 
marketing  qualities  of  the  American  fruit.  The  sunshine 
method  of  California  is  cheap,  but  cannot  be  as  carefully 
regulated  during  each  stage  of  the  process  as  can  the  evapo- 
rator system.  Early  fall  rains  sometimes  damage  prunes 
being  dried  in  the  sun. 

The  prunes  are  dipped  in  a  solution  formed  by  dissolving 
a  pound  of  concentrated  lye  in  about  twenty  gallons  of  water. 
This  is  kept  at  the  boiling  point,  and  when  the  prunes  are 
dipped  into  it  the  lye  causes  the  tough  skin  to  become  tender, 
facilitating  the  escape  of  moisture  from  the  fruit.  The  prunes 
are  then  rinsed  in  clear  water,  and  in  some  cases  are  allowed 
to  roll  down  an  incline  provided  with  many  needle-like  points 
which  pierce  the  skin  and  hasten  further  the  process  of  drying. 
The  fruit  is  then  placed  on  trays  out-of-doors,  or  in  the 
evaporators,  after  which  it  is  allowed  to  stand  for  several 
days  under  conditions  where  escape  of  moisture  will  be  much 
less  rapid.  It  is  then  "processed";  that  is,  dipped  in  boiling 
water,  or  boiling  water  with  glycerine  added  to  it,  or  sub- 
jected to  a  steam  bath.  This  sterilizes  the  fruit,  cleanses  it, 
and  imparts  a  lustrous  appearance.  The  product  is  then 
ready  to  be  packed  and  shipped. 

The  curculio,  plum  gouger,  aphis,  and  scales  are  among  the 
most  common  insects  infesting  plum  orchards.  Crown-gall 


DECIDUOUS  FRUITS  189 

or  root-knot,  black-knot  of  the  branches,  and  leaf-curl  are 
some  of  the  diseases  frequently  occurring  on  plums.  (See 
Chapter  XVII.) 

Most  Japanese  and  some  European  plums  are  self -sterile. 
Single  varieties  of  these  self-sterile  sorts  should  have  rows  of 
other  kinds  blooming  at  the  same  time  planted  with  them. 
If  a  self-sterile  variety  is  planted  alone  in  an  orchard,  it  will 
not,  of  course,  bear  fruit. 

282.  The  cherry  was  common  in  Greece  as  early  as  300 
B.  C.  Pliny  states  that  it  was  brought  to  Rome  about  60 
B.  C.  From  the  sweet  and  sour  cherry  of  the  Old  World, 
the  cultivated  varieties  were  developed. 

The  sweet  cherry  is  a  tall  tree,  wild  in  Europe  and  central 
Asia,  and  the  cultivated  forms  are  likewise  strong  upright 
growing  trees.  The  sour  cherry  is  a  shrub,  wild  in  Asia 
Minor  and  perhaps  in  southeastern  Europe,  and  the  culti- 
vated form  is  a  rather  small  spreading  tree  or  tall  shrub. 
Among  prominent  varieties  of  the  sweet  cherry  are  the  Ad- 
vance, Lewelling,  Bing,  Burbank,  Black  Republican,  Napo- 
leon, and  Tartarian ;  of  the  sour  cherry,  Morello,  Richmond, 
and  Montmorency. 

In  comparing  the  sour  with  the  sweet  cherry,  U.  P.  Hed- 
rick  says:1  "The  sour  cherry  is  very  cosmopolitan,  thriving 
in  many  soils;  is  able  to  withstand  heat,  cold  and  great  at- 
mospheric dryness,  if  the  soil  contain  moisture;  and  though 
it  responds  to  good  care,  it  grows  under  neglect  better  than 
any  other  tree-fruit.  The  sour  cherry,  too,  is  rather  less 
inviting  to  insects  and  fungi  than  most  other  stone-fruits, 
being  practically  immune  to  the  dreaded  San  Jose  scale.  On 
the  other  hand  the  sweet  cherry  is  very  fastidious  as  to  soils, 
is  lacking  in  hardiness  to  both  heat  and  cold  and  is  a  prey  to 
many  insects  and  subject  to  all  the  ills  to  which  stone-fruits 
are  heir;  it  is  grown  at  its  best  in  but  few  and  comparatively 
limited  areas,  though  these  are  very  widely  distributed." 

»  Hedrick,  Cherries  of  New  York. 


190  HORTICULTURE  FOR  SCHOOLS 

This  statement  explains  why  the  cultivation  of  the  sweet 
cherry  is  so  limited  in  North  America.  Its  commercial  pro- 
duction is  confined  to  California,  Oregon,  parts  of  Montana, 
the  Hudson  Valley,  western  New  York,  and  western  Michi- 
gan in  the  United  States;  and  in  Canada  to  that  part  of 
Ontario  along  the  northern  shore  of  Lake  Erie  and  to  the 
interior  parts  of  British  Columbia. 

The  sour  cherry  is  adapted  over  a  much  wider  territory. 
It  is  grown  extensively  along  Lakes  Ontario  and  Michigan, 
and  throughout  the  eastern  and  central  states.  In  Canada 
sour  cherries  are  produced  mainly  in  Ontario,  Nova  Scotia, 
Prince  Edward  Island,  Quebec,  and  British  Columbia. 

It  is  of  interest  to  note  that  the  seven  leading  cherry- 
producing  states  are:  California,  Oregon,  Michigan,  New 
York,  Pennsylvania,  Ohio,  and  Wisconsin.  Very  few  cherries 
of  any  kind  are  grown  in  the  South. 

Nearly  all  varieties  of  sweet  cherries  are  self -sterile ;  there- 
fore, several  kinds  should  be  planted  in  rows  in  the  orchard 
for  pollination  purposes. 

The  cherry,  however,  is  primarily  a  home  fruit  and  the 
greater  part  of  the  fruit  raised  in  the  United  States  is  con- 
sumed on  the  farms  where  grown.  The  tree  does  not  require 
specialized  care,  as  does  the  peach.  The  sour  cherry  is  re- 
markably resistant  to  insect  enemies  and  plant  diseases,  and 
both  the  sweet  and  sour  forms  require  little  attention  in  the 
way  of  pruning  after  the  framework  of  the  tree  has  become 
well  established.  The  tree  also  thrives  with  less  attention  to 
soil  fertilization  than  do  the  other  orchard  fruits.  On  the 
other  hand,  many  orchards  large  and  small  have  suffered  neg- 
lect because  they  do  moderately  well  even  under  adverse 
conditions.  With  good  care  they  would  far  more  than  pay 
for  the  increased  cost  of  attention. 

Those  communities  that  excel  in  the  raising  of  cherries  give 
careful  attention  to  cultivation,  pruning,  control  of  insects, 
fertilization,  cover-crops,  and  harvesting;  and  the  trees  re- 


DECIDUOUS  FRUITS  191 

spond  in  quantity  and  quality  of  fruit  to  the  care  which  they 
receive. 

It  is  interesting  to  note  that  the  famous  cherries  of  Japan 
have  been  developed  for  flowers,  and  not  for  fruit.  Prunus 
serrulata  and  P.  Lannesiana,  the  Japanese  cherries,  bear 
fruits  about  as  large  as  a  small  pea,  but  the  trees  are  of  such 
striking  appearance  when  in  blossom  that  cherry  flowering 
time  is,  in  Japan,  a  time  of  especial  festivity.  "The  sunshine 
that  attends  cherry  blooming  time  in  April,"  says  one  author, 
"the  magnificence  of  the  flower-laden  boughs  and  the  pic- 
turesque flutter  of  the  falling  petals  inspired  an  ancient  poet 
to  liken  the  cherry  to  the  'soul  of  Yamato'  (Japan),  and  it 
has  ever  since  been  thus  regarded." 

NUTS 

283.  The  almond. — References  to  the  almond  in  Biblical 
literature  show  that  it  has  been  known  to  mankind  for  many 
centuries.  At  present,  wild  forms  are  found  in  the  Mediter- 
ranean region.  Edible  varieties,  probably  developed  from  the 
native  wild  forms,  were  early  distributed  over  many  parts  of 
Asia,  Europe,  and  Africa.  They  are  now  grown  in  large 
quantities  in  Spain,  France,  Italy,  Palestine,  and  in  certain 
tropical  islands.  Various  kinds  of  almonds  were  introduced 
into  the  United  States  by  the  Department  of  Agriculture  and 
by  nursery  firms.  Tests  disclosed  the  fact  that  the  almond 
could  be  grown  successfully  only  in  a  few  sections.  Commer- 
cial plantings  are  now  found  mainly  in  the  valleys  and  foot- 
hills of  California,  where  the  warm  dry  climate  is  especially 
favorable  to  its  production.  Fully  80,000  acres  have  been 
planted,  some  of  which  have  not  yet  come  into  bearing.  The 
annual  crop  averages  about  8,000,000  pounds.  A  few  com- 
mercial orchards  of  almonds  are  located  in  Washington,  Utah, 
Nevada,  and  Arizona,  but  in  these  states  frosts  in  spring  and 
freezing  in  winter  make  the  almond  an  uncertain  and  un- 
profitable crop. 


192  HORTICULTURE  FOR  SCHOOLS 

As  the  almond  blooms  very  early  in  the  spring  (February  1 
to  March  20,  depending  on  the  variety  and  district),  it  is  very 
likely  to  be  injured  by  spring  frosts  except  in  the  most  favor- 
able locations,  such  as  the  low  foothill  regions  and  somewhat 
elevated  portions  of  the  large  interior  valleys  of  California, 
where  the  air  drainage  is  good  and  frost  not  likely  to  occur 
at  blooming  time. 

All  commercial  varieties  of  almonds  are  self -sterile,  insofar 
as  they  have  been  tested,  and  some  have  been  found  to  be 
inter-sterile.  The  varieties  for  inter-planting  and  for  pollina- 
tion, therefore,  must  be  selected  very  carefully. 

The  almond  is  propagated  by  budding  upon  almond  or 
peach  stocks.  It  thrives  and  produces  best  on  deep  well- 
drained  soils.  A  moderate  amount  of  moisture  is  necessary. 

The  California  Almond  Growers'  Exchange  is  the  principal 
marketing  agency  for  almonds  grown  in  this  country.  This 
cooperative  organization  is  similar  in  its  scope  to  the  other 
farmers'  cooperative  agencies  mentioned  in  Chapter  XIX. 

The  almond  is  placed  on  the  market  both  in  the  shell  and 
as  a  shelled  product.  Almonds  and  almond  paste  are  used 
in  the  making  of  many  confections. 

The  almond  tree  is  subject  to  few  diseases  or  insect  pests. 

Crown-gall  is  rather  common  (see  Chapter  XVII)  and 
shot-hole  fungus  sometimes  appears.  The  latter  is  controlled 
by  spraying  with  lime-sulfur  solution.  The  most  common 
insect  pest  is  the  red-spider,  which  multiplies  rapidly  in  the 
hot  summer  months.  Sulfur  is  applied  as  often  as  the  red- 
spider  becomes  troublesome. 

284.  The  walnut. — Black  walnuts  of  one  kind  or  another 
have  been  found  in  nearly  every  state  and  in  parts  of  Canada. 
The  Persian  (English)  walnut,  has  been  tested  in  many 
sections  of  the  United  States,  but  did  not  thrive  except 
in  favored  districts.  It  is  now  grown  commercially  in  the 
Pacific  states  and  especially  in  California.  The  latter  state 
has  approximately  75,000  acres  of  walnut  plantings.  On 


DECIDUOUS  FRUITS  193 

account  of  the  large  size  the  trees  attain,  they  are  planted 
farther  apart  than  are  other  orchard  trees.  They  are  propa- 
gated by  budding  or  grafting  the  best  varieties  of  Persian 
walnuts  upon  black  walnut  stock. 

When  the  walnuts  become  mature  on  the  trees,  most  of 
them  drop  and  are  picked  up  by  hand.  Those  which  do  not 
drop  are  shaken  from  the  tree  by  the  use  of  poles  with  hook? 
at  the  ends.  Many  of  the  nuts  drop  free  of  the  hulls  and 
those  which  do  not  are  hulled  by  hand  or  are  run  through  a 
revolving  cylinder  which  removes  the  hulls  readily.  The  nuts 
are  left  to  cure  in  trays  or  in  well-ventilated  drying  bins  for 
a  few  days.  After  the  curing  process,  the  nuts  are  sorted  and 
are  bleached  by  being  run  through  a  bleaching  solution.  They 
are  then  graded  according  to  size  and  are  ready  for  marketing. 
Most  of  the  Persian  walnut  crop  in  this  country  is  placed  on 
the  market  by  a  cooperative  association  of  growers  known  as 
the  California  Walnut  Growers'  Association. 

Blight  is  a  common  disease  affecting  the  walnut.  This 
bacterial  disease  is  especially  destructive  to  the  young  and 
tender  growth  and  to  the  nuts.  When  blight  attacks  the 
nuts  early,  they  turn  black  and  drop,  and  when  it  attacks 
them  later  their  development  is  hindered.  The  walnut  aphis 
is  a  troublesome  insect  pest.  It  is  controlled  by  applying  a 
nicotine  dust  preparation  (made  of  nicotine  dust  mixed  with 
finely  powdered  kaolin)  by  means  of  a  dusting  machine.  In 
recent  years  the  codlin-moth  has  been  troublesome,  the  larva 
of  which  enters  the  nuts. 

285.  The  pecan  is  native  to  the  United  States.  Wild 
forms  are  found  in  several  of  the  southern  states  in  the 
Mississippi  basin.  From  these  a  number  of  excellent  varie- 
ties have  been  derived.  The  pecan  has  become  one  of  the 
most  popular  of  the  nuts  and  the  best  varieties  sell  at  good 
prices.  It  is  planted  widely  in  southeastern  United  States, 
the  most  extensive  plantings  being  in  Georgia,  Alabama,  and 
northern  Florida.  As  pecans  do  not  come  true  to  seed,  the 


194  HORTICULTURE  FOR  SCHOOLS 

trees  are  propagated  by  budding  or  grafting  upon  seedling 
stock.  "A  deep,  fertile  soil,  sufficiently  porous  to  admit  of 
free  root  growth,  well-drained  yet  by  no  means  dry,  is  con- 
sidered best  adapted  to  pecan  culture.  Localities  in  which 
the  water  table  is  within  reach  of  the  taproot  seem  to  be 
preferred  by  the  pecan.  It  is  essential  that  the  trees  be  not 
allowed  to  remain  in  standing  water  for  any  length  of  time, 
although  an  occasional  overflow  to  a  depth  of  several  feet 
apparently  is  beneficial  rather  than  harmful."1 

The  pecan  rosette  is  one  of  the  troublesome  diseases,  and 
the  case-bearer  is  very  damaging  to  some  varieties  in  some 
seasons. 

286.  Other  nuts. — The  hazelnut  is  found  in  many  of  the 
cooler  parts  of  the  United  States  in  its  wild  forms.  The 
filbert  is  a  related  fruit;  it  has  long  been  known  in  Europe. 
Many  improved  varieties  of  the  nut  are  now  grown  in  North 
America.  Some  extensive  plantings  of  filberts  have  been 
made  in  the  Pacific  Northwest.  Harvesting  is  done  promptly 
as  soon  as  the  husks  become  brown.  The  nuts  are  spread  out 
to  dry,  after  which  the  husks  are  removed. 

The  pistache  is  a  slow-growing  tree  which  thrives  in  mild 
climates.  De  Candolle  states  that  it  is  a  native  of  Persia  and 
Syria.  In  the  United  States  it  is  grown  principally  in  Cali- 
fornia and  Texas.  The  small  nuts  are  borne  in  clusters. 
The  shells  are  thin,  smooth,  and  tough.  The  kernels  are 
green  in  color,  have  a  pleasant  flavor,  and  are  much  sought 
after  by  confectioners. 

The  well-known  chestnut,  which  has  been  popular  as  a 
roasted  nut  and  has  been  widely  grown  in  the  eastern  United 
States,  is  rapidly  disappearing  owing  to  the  destructive  effects 
of  the  chestnut  blight. 

The  hickories  include,  besides  the  pecan,  the  shagbark, 
shellbark,  and  pignut.  All  the  species  are  slow-growing  trees 
which  require  well-drained  soils  for  their  best  development. 

1  C.  A.  Reed,  Farmers'  Bull.  700,  U.  S.  Dept.  Agric. 


DECIDUOUS  FRUITS  195 

The    hickories   are    widely    distributed    over   the   eastern, 
central,  and  southern  parts  of  the  United  States. 

EXERCISES 

EXERCISE  I. — Kinds  of  fruit  grown. 

Materials. — Orchard  trees  in  your  locality. 

Procedure. — (1)  Make  a  list  of  fruit-trees  in  your  locality  and  classify 
them  into  deciduous  and  evergreen  trees.  (2)  Visit  a  few  of  the  leading 
orchards  in  your  locality.  Note  the  type  of  soil,  irrigation,  drainage, 
cultivation,  fertilization,  types  of  pruning,  and  so  forth. 

EXERCISE  II. — Distribution  of  species  of  fruit. 

Materials. — Large  outline  map  of  the  United  States,  United  States 
Department  of  Agriculture  Yearbook,  census  reports,  Cyclopedia  of 
Horticulture,  atlases. 

Procedure. — Look  up  the  publications  mentioned  in  the  districts  of 
the  United  States  where  certain  fruits  (in  which  you  are  especially 
interested)  are  grown  and  indicate  the  places  for  each  fruit  on  the  out- 
line map.  Read  up  in  atlases  the  kinds  of  climate  found  in  the  different 
states  in  which  the  fruit  is  raised.  Note  the  range  of  climate  in  which 
each  fruit  thrives. 

EXERCISE  III. — Plan  for  home  orchard. 

Materials. — Map-paper,  notebook,  T-square,  drawing  triangles,  ruler. 

Procedure. — (1)  Draw  a  plan  for  a  home  orchard.  Indicate  the  kinds 
of  trees  desired,  planting  distances,  and  the  like.  (2)  Make  a  schedule 
of  operations  necessary  for  the  care  of  this  home  orchard  for  one  year. 

EXERCISE  IV. — Project.  Look  up  in  as  many  references  as  possible 
all  the  facts  you  can  find  in  regard  to  the  fruit  you  wish  to  select  for 
your  project  exercise.  Write  an  essay  based  on  the  facts  thus  learned 
as  preliminary  to  your  project. 


CHAPTER  XIV 
SEMI-TROPICAL  FRUITS 

THE  principal  fruits  grown  in  the  subtropical  sections  of 
the  United  States  are  members  of  the  genus  Citrus.  Olives 
and  figs  are  produced  in  California  and  the  South,  and  also 
a  few  other  semi-tropical  fruits  of  minor  importance. 

CITRUS  FRUITS 

The  cultivation  of  citrus  fruits  on  a  commercial  scale  is  a 
comparatively  new  horticultural  enterprise  in  the  United 
States.  The  oranges  and  lemons  used  in  this  country  thirty 
years  ago  were  imported  almost  entirely  from  Italy,  Sicily, 
and  Spain.  In  the  year  1919,  the  value  of  the  citrus  crop  in 
the  United  States  was  almost  one  hundred  and  fifty  million 
dollars.  Of  this  amount,  two-thirds  came  from  California, 
almost  one-third  from  Florida,  and  a  smaller  amount  from 
Louisiana,  Mississippi,  and  Texas. 

287.  History. — De  Candolle  writes  that,  at  the  beginning 
of  the  Christian  Era,  the  orange  and  its  allied  forms,  with  the 
possible  exception  of  the  citron,  were  unknown.  These  fruits 
grow  wild  in  southeastern  and  southern  Asia  and  were  intro- 
duced to  America  by  way  of  the  Mediterranean.  A  few 
plants  in  America  are  related  to  the  genus  Citrus,  but  one 
must  travel  to  the  other  side  of  the  world  to  find  the  fruit  in 
its  native  habitat. 

From  its  original  home  it  was  carried  first  to  India,  and 
thence  to  Italy  and  Spain,  where  it  is  today  grown  in  large 
quantities.  From  Europe  it  was  brought  to  the  West  Indies, 
to  South  America  and  to  Florida,  forming  the  basis  of 

196 


SEMI-TROPICAL  FRUITS 


197 


orange-culture  there ;  and  in  1872  two  trees,  the  buds  of  which 
came  originally  from  South  America,  were  planted  in  River- 
side, California.  These  two  trees  proved,  on  fruiting,  to  be  a 
new  variety,  seedless,  and  possessing  especially  fine  qualities. 
The  good  qualities  were  quickly  recognized,  and  the  fruit, 
named  by  the  original 
growers  the  Washington 
Navel  (Fig.  Ill),  became 
the  foundation  for  the 
industry  in  California. 

It  is  especially  worthy 
of  note  that  this  fruit, 
which  originated  in  the 
tropics,  possesses  quali- 
ties when  grown  in  the 
temperate  zone  of  which 
it  gave  no  hint  in  its  orig- 
inal habitat.  Not  only  is 
the  fruit  vastly  superior 
in  flavor,  having  a  spright- 

i.  i          .    •  n-i—J     FIG.  111. — One  of  the  parent  Washington  Na- 

ImeSSana  Zest  in  marked        Vel  orange  trees  still  growing  in  Riverside, 

contrast  with  the  sweet 

insipid  article  of  the  tropics,  but  it  has  keeping  qualities 
also  that  make  it  vastly  superior  for  commercial  purposes 
to  the  orange  and  lemon  of  warmer  climes. 

288.  Frost. — The  cultivation  of  citrus  fruits  in  America 
has  been  attended  by  difficulties  of  many  kinds.  To  begin 
with,  these  fruits  came  originally  from  the  tropics,  and  trop- 
ical plants  are,  of  course,  extremely  sensitive  to  cold.  Trop- 
ical vegetables,  such  as  the  bean  and  the  watermelon,  are 
under  successful  cultivation,  but  they  grow  only  during  the 
summer  and  their  sensitiveness  to  frost  in  the  spring  and  fall 
is  well  known.  The  citrus  tree  must  be  protected  during  the 
entire  year,  for  the  fruit  is  still  growing  in  the  coldest  parts 
of  the  winter.  California  and  Florida,  the  former  in  1913 


198  HORTICULTURE  FOR  SCHOOLS 

and  1922,  the  latter  in  1894,  found  by  bitter  experience  by 
how  narrow  a  margin  of  temperature  these  trees  are  kept 
alive.  The  cold  was  so  severe  that  a  large  part  of  the  crop 
was  ruined  and,  in  many  instances,  the  trees  were  killed  to 
the  ground.  Had  the  thermometer  dropped  a  few  degrees 
lower  in  either  case,  the  industry  in  the  states  concerned 
would  have  been  very  largely  wiped  out. 

The  danger  from  frost  is  ever  present.  The  orange  will 
stand  a  temperature  of  25  degrees  without  serious  damage, 
but  the  lemon  will  be  injured  rather  badly.  Elaborate  pre- 
cautions have  to  be  taken,  therefore,  in  the  way  of  orchard 
heating;  and  it  is  no  uncommon  sight  in  the  citrus  district, 
during  the  early  morning  hours  of  December,  January,  and 
February,  to  see  the  fires  burning  in  thousands  of  orchard 
heaters  of  every  imaginable  type.  Some  varieties  of  Navel 
oranges  .are  more  susceptible  to  injury  by  frost  than  are 
others;  and  it  is  hoped  that  in  the  course  of  time  more  re- 
sistant forms  will  be  developed  which  will  retain  the  good 
qualities  of  the  cultivated  orange  of  today. 

289.  Marketing. — The  marketing  of  citrus  fruit  has 
always  been  a  perplexing  problem.  The  greater  part  of  the 
crop  is  shipped  hundreds,  in  many  cases,  thousands  of  miles, 
and  it  has  been  necessary  to  devise  an  elaborate  system  of 
refrigerator-car  service  so  that  the  fruit  can  be  kept  cool 
from  the  time  it  leaves  the  packing-house  until  the  boxes  are 
removed  from  the  car  in  some  distant  part  of  the  country. 

Frequently  the  fruit  colors  before  it  tastes  sweet  and  the 
United  States  Government  and  the  cooperative  marketing 
organizations,  working  together,  have  attempted  to  protect 
the  consumer  by  insisting  on  a  standard  of  sweetness  which 
would  be  satisfactory  to  the  person  eating  the  fruit.  The 
method  by  which  this  standard  was  established  is  known  as 
the  eight-to-one  test.  The  fruit  is  considered  ripe  when  there 
are  eight  parts  of  soluble  solids  in  the  fruit  to  each  part  of 
acid.  The  soluble  solids  are  for  the  most  part  sugars,  and 


SEMI-TROPICAL  FRUITS  199 

fruit  which  comes  up  to  this  standard  is  satisfactory  from  the 
point  of  sweetness  to  the  average  consumer. 

290.  Insect  pests. — Orange  and  lemon  trees  are  subject 
to  the  depredations  of  many  insect  enemies,  but  especially  of 
that  group  known  as  the  scale  insects.    Wherever  the  orange 
tree  grows,  scale  insects  of  some  sort  are  almost  certain  to  be 
found  in  abundant  quantity.    The  type  causing  most  injury 
varies  in  the  different  localities,  depending  on  climatic  con- 
ditions and  other  factors.    In  Florida  the  chief  pests  are  the 
white-fly,  rust-mites,  and  scale  insects.    In  California  the  red, 
black,  brown,  and  citricola  scales,  and  the  mealy  bug  give 
most  trouble. 

291 .  Control  of  insects. — There  are  two  methods  of  insect 
control;    spraying  and  fumigation.     Spraying  is  practiced 
most  commonly  in  Florida,  fumigation  in  California.    The 
former  is  cheaper  but  needs  to  be  repeated  much  oftener,  and 
constant  care  has  to  be  exercised  not  to  injure  the  evergreen 
foliage  of  the  tree. 

The  fumigation  method,  also,  must  be  performed  with 
great  care.  If  the  temperature  is  too  low  or  too  high,  or  if 
the  atmosphere  contains  too  much  water-vapor,  the  foliage 
and  fruit  may  be  seriously  injured.  For  this  reason,  the  work 
is  always  done  at  night,  and  care  is  exercised  at  each  step  of 
the  process  to  avoid  possible  injury  to  the  tree. 

292.  Citrus  canker. — In  recent  years  there  appeared  in 
Florida  a  citrus  disease  of  such  serious  nature  that  the  aid  of 
the  United  States  Government  was  invoked  to  bring  about 
its  control.     This  was  the  so-called  citrus  canker.     It  is  an 
exceedingly  virulent  disease,  attacking  not  only  leaves  and 
twigs,  but  fruit  and  stems  as  well.    In  its  efforts  to  control 
citrus  canker,  the  United  States  Department  of  Agriculture 
maintained   a   rigid    quarantine  wherever  the  disease  was 
known  to  exist,  in  order  to  prevent  its  spread  to  new  locali- 
ties; and  all  diseased  trees  were  burned  as  soon  as  they  were 
discovered.     A  large  appropriation  for  carrying  out  these 


200  HORTICULTURE  FOR  SCHOOLS 

provisions  was  supplemented  by  funds  from  several  states. 
At  the  present  time  the  work  of  control  has  apparently 
resulted  in  the  eradication  of  the  disease. 

What  has  been  said  about  the  control  of  canker  illus- 
trates very  well  some  fundamental  features  of  disease 
control.  Constant  watchfulness,  the  destruction  of  diseased 
trees  wherever  practicable,  and  the  maintenance  of  rigid 
quarantines,  are  the  three  means  most  likely  to  be  effective 
in  the  case  of  all  new  diseases,  especially  if  eradication  is  at 
all  possible. 

293.  The  future  of  the  citrus  industry. — A  considerable 
acreage  is  yet  available  for  citrus  planting;  but  year  by  year, 
some  localities  prove  to  be  better  than  others  for  the  citrus 
fruits,  and  there  is  a  slow  but  natural  process  of  adjustment 
going  on.    This  is  mentioned  because  it  is  true  not  only  of 
oranges  but  of  other  fruits  as  well.     Under  the  spell  of  a 
temporary  enthusiasm  the  planting  of  some  type  of  fruit  will 
be  pushed  far  beyond  the  limits  of  the  regions  adapted  to  it ; 
then  will  come  adverse  seasons;    many  plantings  will  be 
neglected  and  will  perish,  but  a  few  in  especially  suitable 
locations  will  persist.    Thus  the  industry  is  extended.    The 
process  is  hard  on  those  who  are  carried  away  by  their  tem- 
porary enthusiasms,  to  the  loss,  it  may  be,  of  all  they  possess. 

294.  The  pomelo. — Even  a  brief  discussion  of  citrus  fruits 
would  be  incomplete  without  some  mention  of  the  pomelo, 
known  commercially  as  grapefruit.     The  fruit  is  borne  in 
clusters  of  three  to  twenty,  hence  perhaps  its  popular  name. 
It  was  brought  to  Florida  by  the  Spaniards  in  very  early 
times,  and  at  first  was  grown  in  gardens  merely  as  an  orna- 
mental plant.    It  is  only  in  the  last  quarter  of  a  century  that 
the  pomelo  has  assumed  commercial  importance.    This  some- 
what bitter  fruit  has  proved  both  wholesome  and  appetizing, 
and  has  come  to  be  widely  used  as  a  breakfast  and  salad  dish. 
The  Florida  pomelos  are  preferred  in  the  market,  although  a 
considerable  quantity  of  the  fruit  is  raised  in  California.    Its 


SEMI-TROPICAL  FRUITS  201 

cultivation  is  similar  to  that  of  the  orange,  as  are  the  market- 
ing problems  connected  with  it. 

THE  OLIVE 

295.  Although  the  exact  origin  of  the  olive  is  obscure, 
there  is  no  doubt  that  it  is  one  of  the  oldest  horticultural 
possessions  of  the  race.  References  to  it  in  the  Old  Testa- 
ment1 show  that  the  Hebrews  early  knew  it  as  a  domesticated 
plant.  A  myth  of  ancient  Greece  relates  that  in  a  contest 
between  Minerva  and  Neptune  as  to  which  could  give  the 
most  useful  gift  to  man,  Neptune  gave  the  horse  and  Minerva 
the  olive.  Branches  of  the  olive  have  been  found  in  the 
ancient  mummy  cases  of  the  Egyptians,  and  early  Egyptian 
sculpture  illustrates  the  manner  of  the  extraction  of  olive  oil. 

The  olive  was  brought  to  California  by  the  early  Spanish 
settlers.  It  was  first  known  in  the  Mission  gardens  from 
which  its  culture  spread  gradually.  In  about  1885  a  wave  of 
enthusiasm  for  olive-growing  swept  the  state,  and  from  that 
time  until  1900  extensive  plantings  were  made.  Some  of 
these  were  in  such  unsuitable  locations  that  they  have  since 
been  dug  up.  At  the  present  time  the  olive  is  grown  com- 
mercially in  California  and  in  parts  of  Arizona. 

The  olive  is  such  a  thrifty  grower  that  if  the  top  is  cut  off 
new  shoots  will  grow  from  the  stump.  The  trees  may  attain 
a  great  age,  sometimes  living  three  hundred  years.  The  olive 
is  propagated  easily  by  cuttings.  It  is  more  tolerant  of  poor 
and  rocky  soils  than  are  other  orchard  trees,  but  produces 
maximum  crops  of  best  quality  only  where  the  soil  is  fairly 
good  and  the  moisture  moderately  plentiful.  The  tree  is  an 
evergreen,  keeping  its  foliage  the  year  round.  It  blossoms 
late  in  the  spring  and  is,  therefore,  not  especially  subject  to 
injury  by  spring  frosts.  Hot  dry  winds,  however,  sometimes 
cause  the  blossoms  to  drop.  Since  the  olives  ripen  on  the  tree 

»  Deuteronomy  XXVIII,  40;  Exodus  XXIII,  11 ;  Deuteronomy  XXIV,  20. 


202  HORTICULTURE  FOR  SCHOOLS 

in  the  late  fall,  they  may  be  frosted  at  that  time  in  unfavor- 
able localities.  In  general,  the  olive  requires  a  dry  warm 
climate. 

Olives  are  grown  for  pickling  and  for  their  oil.  They  are 
pickled  either  green  or  ripe.  Certain  varieties  are  better 
adapted  than  others  for  making  the  green  pickles.  The 
olives  are  picked  from  the  tree  by  hand,  soaked  in  lye  solu- 
tions to  remove  their  extreme  bitterness,  washed  in  water, 
and  then  immersed  in  salt  solutions.  Pickled  olives  are  now 
put  through  a  process  by  which  they  are  heated  to  a  high 
temperature  under  pressure,  to  destroy  any  injurious  bacteria 
that  may  be  present.  Olive  oil  is  secured  by  pressing  the 
ripe  olives.  The  oil  which  is  obtained  first  is  best  in  quality. 

THE  FIG 

296.  The  fig,  a  native  of  the  Persian  Gulf  region,  has 
found  a  congenial  home  in  the  warmer  parts  of  the  United 
States.  It  is  grown  in  the  bush  form  where  freezing  is  likely 
to  occur,  otherwise  the  tree  form  is  preferred.  Although  the 
fig  tree  is  adapted  to  a  great  diversity  of  land,  heavy  soils, 
retentive  of  moisture  but  well-drained,  are  best.  Nematodes 
(a  kind  of  small  worm)  are  less  likely  to  prove  troublesome 
than  in  light  sandy  soils.  The  fig  tree  suffers  greatly  from  lack 
of  drainage  and  should  not  be  planted  in  water-logged  land. 
As  fig  trees  are  shallow-rooted,  care  in  cultivation  is  necessary 
to  prevent  injury  to  the  roots. 

The  fruit  of  the  fig  consists  of  an  enlarged  fleshy  hollow 
receptacle,  having  its  flowers  on  the  inner  surface.  Figs 
possess  three  kinds  of  flowers:  namely,  pistillate,  staminate, 
and  gall  flowers.  Pistillate  (female)  flowers  are,  as  a  rule, 
the  only  ones  present  in  the  edible  varieties.  Staminate  and 
gall  flowers  are  found  in  the  wild  or  caprifigs.  The  latter  are 
really  pistillate  flowers  modified  to  suit  the  needs  of  the  fig 
wasps  in  laying  the  eggs  and  hatching  their  young.  Most 
varieties  do  not  require  cross-pollination  in  order  to  produce 


SEMI-TROPICAL  FRUITS  203 

fruit,  but  the  Smyrna  fig  does.  For  a  long  time  attempts  to 
grow  this  type  in  America  failed  because  of  lack  of  knowl- 
edge of  the  necessity  of  pollination  and  of  the  agency  by 
which  pollen  from  the  wild  figs  was  introduced  through  the 
small  opening  or  eye  of  the  Smyrna  on  to  the  stigmas  within. 
It  was  finally  learned  that  the  transfer  of  pollen  was  effected 
by  means  of  a  tiny  fig  wasp.  The  insect  lives  its  life  cycle  in 
the  wild  or  caprifigs,  and  three  crops  of  the  wild  fruit  are 
necessary  in  order  that  there  may  be  figs  the  year  around  so 
that  the  insects  may  not  die  out.  The  proper  kinds  of  capri- 
figs must,  therefore,  be  planted  to  insure  fruit  all  year.  To 
insure  pollination  of  the  Smyrnas,  caprifigs  containing  the 
wasps  are  hung  in  wire  baskets  in  the  Smyrna  trees  when  the 
figs  are  quite  small.  The  female  wasps,  in  crawling  out  of 
the  caprifigs,  become  covered  with  pollen  which  sticks  to 
their  bodies.  They  then  enter  the  Smyrna  figs  through  the 
eye.  The  insects  crawl  around  in  the  fruit  looking  for  the 
short-styled  gall  flowers  such  as  are  found  in  the  caprifig  in 
which  to  lay  their  eggs,  but  finding  nothing  but  the  long- 
styled  female  flowers  they  finally  attempt  to  lay  their  eggs 
in  them.  Meanwhile,  the  insects  in  wandering  around  inside 
the  fig  have  rubbed  off  a  large  amount  of  the  pollen  adhering 
to  their  bodies  upon  the  female  flowers,  and  as  a  consequence 
of  this  pollination,  fruit  will  set. 

Smyrna  figs  can  be  grown  only  in  hot  dry  climates,  and 
will  sour  on  the  tree  if  the  atmosphere  is  at  all  humid.  They 
were  formerly  grown  successfully  only  in  a  part  of  Asiatic 
Turkey  and  were  shipped  from  the  port  of  Smyrna,  but  after 
the  discovery  of  the  methods  of  pollination  accomplished  by  the 
wasps,  this  best  of  all  dried  figs  was  widely  planted  in  Cali- 
fornia and  Arizona,  where  it  is  successfully  grown  in  large  quan- 
tities in  the  hot  dry  portions  of  those  states.  Harvesting  meth- 
ods and  preparing  for  market  are  comparatively  simple.  The 
figs  are  allowed  to  fall  to  the  ground  when  mature,  are  picked 
up  by  hand,  dried,  pressed,  and  packed  for  the  market. 


204  HORTICULTURE  FOR  SCHOOLS 

In  warm  regions  where  the  air  is  too  moist  for  the  successful 
growing  of  the  Smyrna  or  other  white  figs,  dark  figs  are  grown. 
Throughout  the  southern  states,  quantities  of  figs  are  pro- 
duced, which  are  used  and  shipped  fresh,  made  into  preserves, 
or  canned.  Figs  in  the  canned,  preserved,  and  dried  forms, 
are  delicious  and  wholesome  foods. 

297.  Other  semi-tropical  fruits  grown  in  some  parts  of 
the  United  States  are  the  guava,  feijoa,  loquat,  jujube, 
persimmon,  pomegranate,  and  avocado.  Although  all  of 
these  are  produced  to  some  extent,  lack  of  space  forbids  a 
description  of  them  in  this  book. 

EXERCISES 

EXERCISE  I. — Citrus  fruits. 

Materials. — At  least  one  each  of  the  following  fruits:  Washington 
Navel  orange,  seedling  orange,  lemon,  grapefruit. 

Procedure. — Sketch  each  of  the  above  fruits  bringing  out  typical 
differences  in  size  and  structure.  Note  the  oil  glands  on  the  surface 
of  the  fruit.  Make  a  transverse  section  through  the  center  of  each 
midway  between  stem-end  and  apex.  Make  a  sketch  of  this  section 
showing  the  location  of  segments  and  the  arrangement  of  cells  within 
the  segments. 

Make  another  transverse  section  through  the  center  of  the  Navel 
orange  and  sketch,  bringing  out  similarities  between  the  Navel  and 
the  original  fruit.  It  may  be  mentioned  parenthetically  that  the  Navel 
is  itself  an  orange  within  an  orange. 

In  the  drawings  already  made,  indicate  in  the  case  of  those  fruits 
bearing  seeds  the  points  of  attachment  of  the  seeds.  Note  manner  in 
which  fruit  was  separated  from  the  tree.  Note  especially  the  way  the 
cut  was  made  and  see  if  you  can  detect  any  sign  of  decay  about  this  cut. 

EXERCISE  II. — Comparative  amount  of  acid  in  orange  and  lemon. 

Materials. — Orange  and  lemon,  glass  beaker,  two  graduated  burettes, 
standard  alkali  solution,1  phenol  indicator,  lemon  squeezer,  wire 
strainer. 

Procedure. — Extract  juice  from  orange,  strain  out  coarse  materials, 
pour  into  burette,  measure  out  20  c.c.  of  juice,  and  add  a  few  drops  of 

*  To  the  Instructor:  Make  up  standard  alkali  solution  by  adding  6.25 
grams  sodium-hydroxide  to  1000  c.c.  of  water. 


SEMI-TROPICAL  FRUITS  205 

indicator.  Fill  other  burette  to  zero  mark  with  standard  alkali  solution, 
and  add  solution  to  the  20  c.c.  of  orange  juice,  stirring  constantly  until 
the  color  is  permanently  changed. 

One  c.c.  of  the  solution  neutralizes  approximately  10  m.g.  of  citric 
acid.  How  many  m.g.  of  citric  acid  are  there  in  20  c.c.  of  orange  juice? 

Repeat  using  the  juice  of  the  lemon,  calculating  again  the  number 
of  m.g.  of  citric  acid  in  20  c.c.  of  lemon  juice.  How  does  the  amount 
of  acid  in  a  given  quantity  of  lemon  juice  compare  with  that  in  the 
same  amount  of  orange  juice? 

What  connection  is  there  between  this  fact  and  the  taste  of  each  of 
the  two  fruits? 

EXERCISE  III. — Study  of  varieties. 

Procedure. — Get  in  your  neighborhood  as  many  different  types  and 
varieties  of  citrus  fruits  as  you  can  find.  Arrange  these  in  the  class-room, 
being  careful  that  each  variety  is  named.  Make  a  comparative  study 
of  the  different  fruits,  recording  in  the  notebook  the  essential  facts 
regarding  each  one,  such  as  size,  color,  shape,  period  of  ripening,  suscep- 
tibility to  frost,  commercial  importance,  and  any  other  facts  which  may 
be  ascertained. 

EXERCISE  IV. — Advertising  citrus  fruits. 

Materials. — The  leading  national  magazines. 

Procedure. — Clip  from  magazines  all  the  advertisements  you  can 
find  dealing  with  citrus  fruits.  Make  a  study  of  these  advertisements, 
noting  especially  their  general  appearance  and  their  timeliness,  from 
the  standpoint  of  household  use  and  of  crop  production. 

It  is  said  that  the  citrus  interests  of  the  country  are  among  the 
heaviest  magazine  advertisers.  Notice  how  many  advertising  pages 
there  are  in  the  periodicals  you  are  examining  and  calculate  the  per- 
centage of  the  whole  contributed  by  the  citrus  advertisers. 

EXERCISE  V. — Citrus  projects. 

Procedure. — All  students  having  citrus  projects  should  at  this  time 
prepare  a  detailed  statement  regarding  the  care  of  the  project  and  its 
financial  condition.  This  should  be  presented  to  the  class  in  the  form 
of  a  written  and  oral  report. 


CHAPTER  XV 
SMALL-FRUITS  AND  THE  GRAPE 

IN  every  locality  and  in  nearly  all  gardens,  some  kinds  of 
small-fruits  may  be  grown  successfully.  Whether  straw- 
berries, raspberries,  blackberries,  loganberries,  dewberries, 
currants,  or  gooseberries  are  raised,  the  yield  to  the  square 
rod,  under  favorable  conditions,  is  astonishingly  large. 

THE   STRAWBERRY 

298.  Origin  and  adaptation. — The  origin  of  the  strawberry 
has  not  been  traced,  but  there  are  records  of  its  cultivation  in 
England  in  1483,  and  of  the  appearance  of  improved  sorts  in 
the  eighteenth  century.    About  2000  varieties  of  cultivated 
strawberries  have  been  developed  in  North  America.     The 
improved    American    kinds    have    been    introduced    into 
Europe. 

Since  the  strawberry  is  adapted  to  a  wide  range  of  climate, 
it  is  grown  for  home  use  and  local  market  in  nearly  every 
region  in  the  United  States  and  Canada.  The  principal  areas 
of  commercial  production  are  near  the  large  cities  of  the 
northern  states,  along  the  Atlantic  Coast,  in  the  Mississippi 
Valley,  and  in  parts  of  the  Pacific  states. 

299.  Soils. — The  strawberry  requires  an  abundant  supply 
of  water  and  a  climate  which  is  not  too  hot  nor  dry.    When 
these  conditions  are  present,  it  will  grow  on  many  types  of 
soils,  although  a  rich  loam  is  most  favorable.    Heavy  manur- 
ing is  usually  desirable.    As  the  strawberry  plant  is  a  shallow 
feeder,  it  can  be  grown  on  soils  underlaid  with  hardpan  if  the 
drainage  is  satisfactory. 

206 


SMALL-FRUITS  AND   THE  GRAPE 


207 


300.  Starting  the  plants. — As  stated  in  another  chapter, 
strawberry  plants  are  propagated  by  means  of  runners.    In 
starting  a  new  bed,  young  plants  should  be  used  rather  than 
old  ones  whose  roots  have  become  dark.    Only  strong  and 
healthy  individuals  with  good  root  systems  should  be  set  out. 
The  roots  should  not  be  allowed  to  dry  out.    This  may  be 
avoided  by  keeping  the  plants  in  mud  from  the  time  they  are 
dug  until  they  are  transplanted.     When  shipped  from  a 
distance,  the  roots  are  kept  from  drying  by  a  packing  of 
slightly  moist  sphagnum  moss  or  similar  material.     It  is 
customary  before  planting  to  remove  some  of  the  leaves  and 
to  prune  the  roots  to  about  half  their  normal  length.    It  is 
very  important  that  the  plants  be  set  so  that  the  crown  is 
level  with  the  soil.    Care  should  be  taken  not  to  bury  the 
crown  or  to  set  so  high  that  the  upper  roots  are  exposed 
(Fig.  112).    Failure  to  grow  is  frequently  due  to  the  plants 
not  being  set  at  the  proper  depth.    A  cultivated  crop  should 
be  grown  before  land  is  used  for 

strawberry  plants  in  order  to 
avoid  injury  to  them  from  grubs 
which  inhabit  sod  or  grass  land. 

301.  Planting  systems. — There 
are  several  planting  systems  for 
strawberries,  each  of  which  has 
its  advantages.    In  the  matted- 
row  method  (Plate  VII) ,  the  plants 
are   set   about    eighteen    inches 
apart  in  rows  at  least  four  feet 
distant.    The  plants  are  allowed 
to  run  together  in  narrow  rows, 
and  are  prevented  by  cultivation 
from  running  across  to  the  other 
rows.  This  system  has  the  advan- 
tage of  producing  a  large  number  of  plants  on  a  given  area,  but 
the  berries  are  not  as  large  as  with  some  of  the  other  methods. 


Fid.     112. — Proper   depth    to   set 
strawberry  plants. 


208        HORTICULTURE  FOR  SCHOOLS 

The  hedge-row  system  is  popular  in  some  sections.  The 
plants  are  set  as  described  for  the  matted-row,  but  for  each 
plant  only  one  runner  on  each  side  is  allowed  to  take  root 
in  the  row,  while  all  other  runners  are  removed.  In  this 
method  the  plants  are  rather  close  together  in  the  row,  but 
have  more  room  than  in  the  matted-row  system.  In  the  hill 
system  the  plants  are  usually  set  at  two-foot  intervals  in 
rows  from  three  and  one-half  to  four  feet  apart .  The  plants  are 
cultivated  both  ways  and  are  not  allowed  to  produce  runners. 
The  largest  berries  are  obtained  when  this  system  is  used,  but 
the  total  yields  are  smaller  than  under  the  other  methods. 

302.  Cultivation. — After  the  plants  are   set   out,   they 
should  have  plenty  of  moisture.    Frequent  cultivation  of  the 
soil  is  necessary  to  conserve  the  moisture,  and  irrigation  is 
commonly  resorted  to.    The  plants  are  not  allowed  to  bear 
fruit  the  same  season  as  set,  but  the  blossoms  are  picked  so 
that  the  strength,  which  would  otherwise  be  used  in  develop- 
ing fruit,  goes  to  produce  a  thrifty  growth.    The  plants  are 
not  allowed  to  bear  more  than  two  or  three  years,  and,  since 
after  that  period  the  berries  become  unprofitably  small,  the 
bed  is  plowed  up  and  a  new  one  started  elsewhere. 

303.  Mulching. — In  cold  climates,  clean  straw  free  from 
seeds  or  weeds  is  put  over  the  plant  to  prevent  injury  from 
freezing.    The  straw  is  left  on  until  the  following  spring  when 
it  is  raked  between  the  rows  and  finally  removed  after  the 
berry  crop  is  harvested.    Where  insect  pests  are  troublesome, 
the  tops  are  cut  with  a  mower,  allowed  to  dry  thoroughly,  and 
burned  with  the  straw  in  the  rows.    This  will  not  injure  the 
plants  as  they  will  put  forth  new  leaves.   If  the  mulch  is  left  in 
the  rows  late  in  the  spring,  it  retards  the  blossoming  several  days, 
and  so  may  prevent  the  blossoms  from  being  injured  by  frost. 

304.  Pollination. — In  setting  out  strawberry  plants,  it 
should  not  be  forgotten  that  some  varieties  are  pistillate  only 
and  require  other  kinds  for  pollination  purposes.1 

« See  Chapter  XII. 


SMALL-FRUITS  AND   THE  GRAPE  209 

305.  Harvesting  and  packing. — The  picking  of  the  berries 
at  the  correct  time  and  proper  packing  of  them  are  essential 
to  commercial  success.    Strawberries  are  graded  as  they  are 
picked,  and  are  placed  in  quart,  pint,  or  half-pint  boxes. 
Sometimes  the  berries  of  the  top  layer  are  packed  obliquely 
in  the  box  with  the  stems  downward  and  the  tips  all  pointing 
one  way.    Fancy  packs  of  this  sort  bring  a  better  price  in 
certain  markets  than  the  ordinary  packages.    In  the  picking, 
strawberries  should  not  be  pulled  from  the  calyx,  but  the 
stem  should  be  pinched  off  so  that  a  small  portion  is  left  with 
the  berry.    Berries  to  be  sold  in  the  local  market  can  be 
picked  quite  ripe,  but  those  to  be  shipped  must  be  slightly 
green.    Some  varieties  ship  better  than  others.    Advice  as 
to  the  best  varieties  to  grow  in  any  particular  section  can  be 
obtained  from  local  nurserymen,  and  from  the  state  experi- 
ment stations. 

306.  Insects  and  diseases  of  the  strawberry  can  be  con- 
trolled by  rotation  of  crops,  burning,  and  spraying.1 

307.  Everbearing  strawberry. — Of  late  years  much  in- 
terest has  been  shown  in  everbearing  strawberries.    This  sort 
bears  fruit  more  or  less  continually  from  the  usual  time  in 
early  summer  until  frost  kills  the  blossoms  in  the  autumn. 
They  bear  especially  well  during  the  fall  months.    Everbear- 
ing strawberries  are  of  special  value  in  frosty  localities,  for 
although  frost  may  kill  the  early  blossoms  of  the  season, 
more  will  be  produced  later,  as  is  not  the  case  with  the 
ordinary  kinds.    The  everbearing  strawberry  is  usually- grown 
in  matted  rows.    Its  culture  is  the  same  as  for  the  other  kinds. 

THE   BLACKBERRY 

308.  Origin.  —  The  common  blackberry  grows  wild  in 
many  parts  of  the  country.    Formerly  most  of  the  blackber- 
ries were  obtained  from  the  wild,  but  with  the  increase  in 

1  For  a  detailed  account  the  student  is  referred  to  Fletcher's  Strawberry- 
Growing. 


210  HORTICULTURE  FOR  SCHOOLS 

population  and  the  destruction  of  the  wild  patches  to  make 
room  for  farms,  the  cultivated  blackberry  came  into  promi- 
nence. These  are  as  good  in  flavor  and  are  superior  in  size 
to  the  wild  berries.  Of  the  cultivated  forms  there  are  many 
varieties. 

309.  Requirements  of  the  blackberry. — The  blackberry 
succeeds  in  nearly  all  sections  of  North  America  except  the 
very  coldest.    Even  there  it  can  be  grown  if  given  proper 
winter  protection.    In  hot  dry  regions  the  fruit  will  be  small 
in  size  and  scant  in  quantity,  but  may  be  improved  greatly 
by  irrigation.    The  blackberry  thrives  in  heavy  well-drained 
land,  but  will  succeed  in  many  types  of  soils  if  not  too  wet. 
While  blackberries  prefer  rich  soils,  and  while  the  proper 
addition  of  manure  or  other  fertilizers  increases  the  yield, 
too  much  fertilizing  or  too  rich  land  make  the  growth  of  the 
vines  undesirably  rank. 

310.  Propagation. — Blackberries  may  be  propagated  by 
means  of  suckers  or  by  root-cuttings  according  to  methods 
described  in  the  chapters  on  propagation.1 

311.  Planting  and  training. — Blackberries  should  be  given 
plenty  of  room.    They  are  usually  planted  from  five  to  seven 
feet  apart,  in  rows  from  six  to  twelve  feet  distant,  according 
to  the  variety  and  system  of  training.     The  young  vines 
should  have  the  terminal  shoots  pinched  back  in  the  spring 
as  soon  as  the  plants  reach  a  height  of  two  or  four  feet.    This 
causes  stronger  growth  and  greater  stockiness.    When  the 
laterals  reach  a  length  of  eighteen  or  twenty-four  inches,  they 
are  pinched  back.     As  the  fruit  is  borne  on  the  previous 
season's  growth,  all  the  old  canes  should  be  cut  out  after 
fruiting,  leaving  from  three  to  six  canes  of  the  present  season 
to  bear  fruit  the  following  year.    Blackberry  vines  may  be 
grown  without  support,  may  be  staked,  or  grown  on  a  trellis, 
depending  on  the  preference  of  the  grower,  the  locality,  and 

'  Chapters  IV  and  V. 


SMALL-FRUITS  AND  THE  GRAPE  211 

the  variety.  The  trailing  kinds,  grown  on  a  trellis  or  other 
forms  of  support,  are  usually  kept  cut  back  to  ten  or  twelve 
feet  in  length. 

312.  Pollination. — Most  of  the  blackberries  are  self -fertile 
but  a  few  varieties  are  self -sterile. 

313.  Cultivation. — Blackberries  require  frequent  cultiva- 
tion.    Some  growers  plant  cover-crops  between  the  rows 
where  the  climate  is  humid,  or  an  abundance  of  irrigation 
water  may  be  obtained.    Cultivation  of  blackberries  should 
be  shallow  so  as  not  to  injure  their  roots.     Injured  roots 
produce  large  numbers  of  suckers,  which  become  troublesome. 

314.  Picking  and  shipping. — Blackberries  picked  green  do 
not  ripen  well  in  shipment.    The  best  quality  of  fruit  is  that 
picked  ripe  for  local  use.    In  picking,  packing,  and  shipping, 
care  is  necessary.     Unlike  most  fruits,  blackberries  do  not 
ripen  in  storage.    Blackberries  may  be  eaten  fresh,  canned, 
or  dried;  or  the  juice  may  be  extracted  and  used  as  a  drink. 

315.  Winter  protection. — In   cold   climates,   blackberry 
vines  are  protected  from  freezing  during  the  winter  by  being 
bent  over  and  covered  with  soil  in  the  fall.    In  the  spring  the 
covering  is  removed  and  the  vines  straightened  out. 

316.  Special  varieties  of  blackberries. — The  evergreen 
blackberry,  popular  on  the  Pacific  Coast,  is  said  to  be  un- 
usually resistant  to  disease.    It  is  a  trailer  propagated  by  tip- 
layering.    The  Himalaya  blackberry  bears  a  late  crop  extend- 
ing over  a  considerable  period  of  time.    It  is  a  rampant  grower 
and  produces  abundantly,  but  is  adapted  to  certain  sections 
only.    The  dewberry  is  a  trailing  variety  of  blackberry.    It 
does  well  on  almost  any  type  of  soil.    Like  the  common  black- 
berry it  may  be  propagated  by  root-cuttings,  or  like  the  ever- 
green blackberry,  by  tip-layering.    The  loganberry  was  origi- 
nated by  J.  H.  Logan,  of  Santa  Cruz,  California.  It  is  large, 
shaped  like  a  blackberry,  and  colored  like  a  red  raspberry, 
and  has  a  distinct  and  pleasant  flavor  of  its  own.    This  fruit 
may  be  canned  or  dried  and  its  juice  makes  a  very  fine 


212  HORTICULTURE  FOR  SCHOOLS 

beverage.  It  thrives  and  is  grown  extensively  in  the  Pacific 
Coast  states,  but  will  not  succeed  in  cold  climates.  The 
loganberry  is  propagated  by  tip-layering,  is  trained  on  some 
form  of  trellis,  and  is  cultivated  in  the  same  way  as  the  black- 
berry. The  phenomenal  berry  is  somewhat  similar  to  the 
loganberry.  Since  localities  where  it  will  succeed  are  limited, 
it  is  not  cultivated  extensively. 

THE  EASPBERRY 

317.  Among  the  raspberry  types  are  the  red,  black,  purple, 
and  yellow.     The  red  raspberry  propagates  by  suckers  so 
readily  that  it  is  likely  to  become  a  nuisance.   On  this  account, 
many  growers  plant  in  hills  and  cultivate  in  both  directions. 
Red  raspberries  are  propagated  commercially  by  root-cut- 
tings.   Black  raspberries,  or  "  black-caps/'  are  multiplied  by 
tip-layering.    The  yellow  and  the  purple  varieties  may  be 
propagated  by  either  or  both  of  the  methods  just  mentioned, 
depending  on  the  variety. 

All  types  of  raspberries  succeed  best  in  cool  climates,  con- 
tinuous hot  weather  being  very  unfavorable.  They  require 
thorough  cultivation  and  plenty  of  moisture,  but  the  land 
should  be  well  drained.  They  succeed  on  a  wide  range  of  soils. 

Although  some  of  the  red  raspberries  tend  to  produce  fruit 
in  the  autumn  on  the  same  season's  growth,  for  practical 
purposes  the  fruit  of  all  varieties  may  be  said  to  be,  borne 
upon  growth  of  the  previous  season.  Therefore,  old  wood 
can  be  cut  out  after  fruiting  or  early  in  the  following  spring. 
It  is  customary  to  head  the  young  wood  of  the  black  rasp- 
berries back  to  a  height  that  will  cause  stocky,  well-branched, 
fruitful  plants.  This  should  be  done  with  red  raspberries  also 
in  most  cases. 

CURRANTS  AND  GOOSEBERRIES 

318.  Adaptation. — Both  currants  and  gooseberries  thrive 
in  cool  climates.    They  withstand  intense  cold  and  survive 


SMALL-FRUITS  AND  THE  GRAPE  213 

long  severe  winters.  In  hot  or  dry  regions  they  will  not 
succeed.  As  currants  and  gooseberries  blossom  very  early 
in  the  spring,  attention  must  be  given  to  air  drainage.  They 
should  not  be  planted  on  low  places  where  the  cold  air  is 
likely  to  settle.  Both  of  these  plants  grow  best  on  heavy  and 
moist,  but  well-drained,  soils.  Northern  slopes  are  generally 
preferable.  Currants  and  many  kinds  of  gooseberries  are 
propagated  by  cuttings.  Those  varieties  of  gooseberries 
which  do  not  grow  well  from  cuttings  are  propagated  by 
mound-layering.  (See  paragraph  78.) 

319.  Bearing  habit. — Black  currants  bear  best  on  one- 
year-old  wood.    In  pruning  it  is  customary  to  cut  out  all 
wood  which  has  borne  two  crops,  thinning  the  center.    Six  or 
seven  canes  are  left  on  each  bush. 

Red  and  white  currants  bear  fruit  on  spurs  on  the  old  wood 
and  at  the  base  of  one-year-old  growth.  They  bear  most 
fruit  on  wood  younger  than  four  years.  Pruning  one-year-old 
red  or  white  currants  consists  in  removing  all  but  six  or 
seven  of  the  strongest  shoots.  In  the  following  year,  about 
eight  shoots  are  left,  half  of  them  being  two  years  old,  and  the 
other  half  one  year  old.  The  third  year's  pruning  consists 
in  cutting  out  all  shoots  except  two  or  three  each  of  one-year- 
old,  two-year-old,  and  three-year-old  growth.  The  following 
years,  all  stems  older  than  three  years  are  removed,  leaving 
enough  one-year-old  stems  to  take  their  places. 

With  gooseberries  the  fruit  is  borne  on  one-year-old  wood, 
and  on  one-year-old  spurs  upon  older  growth.  The  early 
pruning  of  the  gooseberry  is  similar  to  that  of  the  currant. 
In  the  later  pruning,  all  stems  which  have  produced  fruit  two 
years  are  removed,  except  in  the  Pacific  Coast  states  where 
it  is  customary  to  allow  the  stems  to  bear  fruit  for  three 
years. 

320.  Cultivation  of  currants  and  gooseberries  is  similar  to 
that  given  other  bush-fruits.    Cultivation  should  be  shallow 
so  as  not  to  injure  the  roots. 


214  HORTICULTURE  FOR  SCHOOLS 

321.  Insect  pests  and  diseases.  —  The  currant-worm, 
currant-aphis,  and  currant-borer  are  common  pests.  The 
first  may  be  destroyed  by  arsenical  sprays  (one  pound  pow- 
der, or  two  pounds  paste  of  lead  arsenate  to  fifty  gallons  of 
water)  applied  at  the  proper  times  to  kill  the  larvae.  Nicotine- 
sulfate  spray  is  used  to  kill  the  currant-aphis.  Borers  are 
difficult  to  reach.  The  only  practical  way  is  to  cut  out  and 
burn  the  infected  canes.  The  San  Jose  scale  sometimes  is 
troublesome  on  both  currants  and  gooseberries.  The  remedy 
is  lime-sulfur  spray  of  winter  strength,  or  oil  emulsions  ap- 
plied while  the  plants  are  dormant. 

Anthracnose  is  a  common  disease  of  the  currant  and  goose- 
berry, as  well  as  of  other  bush-fruits.  It  is  a  fungus,  which 
first  appears  as  brown  spots  on  the  upper  surface  of  the  leaves, 
and  later  makes  the  leaves  turn  yellow  and  drop.  The  disease 
attacks  the  canes  and  fruits.  A  spray  of  lime-sulfur  applied 
while  the  plant  is  dormant  is  helpful.  Applications  of  bor- 
deaux mixture  are  made  during  the  growing  season.  The 
application  of  lime-sulfur  or  bordeaux  is  useful  in  controlling 
other  leaf-spot  diseases. 

Mildew,  another  common  disease,  can  be  controlled  by 
application  of  sulfur. 

Cane-wilt  in  the  currant  is  rather  serious  as  it  is  difficult 
to  control.  The  disease  enters  at  the  buds  and  works  down 
the  stem,  causing  the  fruit  and  leaves  to  die.  The  best 
treatment  is  to  cut  out  and  burn  diseased  canes.  Bordeaux 
mixture  applied  in  the  growing  season  is  recommended. 

In  white  pine  blister-rust  the  fungus  first  starts  on  currant 
or  gooseberry  leaves,  and  then  attacks  pines.  It  finally  kills 
the  trees.  The  disease  cannot  be  spread  among  the  pines 
without  the  aid  of  currant  or  gooseberry  bushes  as  a 
host  plant.  In  localities  where  the  disease  is  present,  no 
attempt  should  be  made  to  grow  currants  or  gooseberries 
within  a  considerable  distance  of  white  pine  trees,  and  all 
wild  gooseberry  or  currant  bushes  should  be  destroyed. 


SMALL-FRUITS  AND   THE  GRAPE  215 


THE  GRAPE  (Plate  VII) 

322.  Origin. — The   grape   is  generally   credited   to   the 
Phoenicians.    These  tradesmen  and  sailors  probably  intro- 
duced it  into  the  countries  that  border  the  Mediterranean. 
It  is  known  that  this  occurred  more  than  three  thousand  years 
ago ;  for  Hesiod,  writing  about  that  time,  describes  the  vine 
and  gives  directions  for  its  care.     But  the  cultivated  grape 
did  not  originate  with  the  Phoenicians.   They  in  turn  received 
it  from  other  peoples,  probably  from  the  region  of  the  Caspian 
Sea.    De  Candolle  thinks  that  the  forms  found  there  represent 
the  wild  progenitors  from  which  the  domesticated  Vitis  vini- 
fera  has  sprung.     This  is  the  grape  of  history.     In  this 
country,  it  is  confined  mostly  to  California. 

323.  The  grape  in  Europe  and  America. — The  grape  has 
been  used  in  Europe  from  earliest  times  primarily  for  the 
making  of  wines.     Hundreds  of  varieties  are  cultivated  in 
that  part  of  the  world  at  the  present  time,  but  all  are  de- 
scended from  the  single  species,  Vitis  vinifera,  which  is  the 
wine-producing  form.    The  American  table  grape  is  another 
product,  and  is  derived  either  directly  from  native  American 
species,  or  from  hybrids  secured  by  crossing  these  with  the 
European  forms.    The  early  settlers  in  America  found  the 
grape  growing  wild  in  great  abundance;  but  so  accustomed 
were  they  to  the  European  point  of  view  that  they  thought 
of  it  only  in  terms  of  the  wine  which  might  be  made  from  it. 
About  the  middle  of  the  last  century,  however,  the  discovery  of 
the  Concord  grape  marked  the  beginning  of  a  new  era  of  Amer- 
ican grape-culture,  founded  on  a  native  American  variety. 

324.  Origin  of  the  Concord. — In  his  work  entitled  The 
Evolution  of  Our  Native  Fruits  Bailey  gives  a  full  account 
of  the  types  of  grapes  that  have  originated  in  America.    In 
speaking  of  the  Concord,  he  says:   "Mr.  Ephraim  W.  Bull 
bought  the  house  at  Concord,  in  which  he  lived,  in  1840. 
That  year,  he  relates,  boys  brought  up  from  the  river  some 


216  HORTICULTURE  FOR  SCHOOLS 

wild  grapes,  and  scattered  them  about  the  place.  A  seedling 
appeared,  evidently  the  offspring  of  these  truant  grapes. 
Mr.  Bull  tended  it,  and  in  1843  he  obtained  a  bunch  of  grapes 
from  it.  He  planted  seeds  of  this  bunch,  and  a  resulting 
plant  fruited  in  1849.  The  fruit  had  such  merit  that  all 
other  seedlings  were  destroyed.  The  new  variety  was  named 
the  Concord.  ...  It  is  the  most  important  type  of  Amer- 
ican grapes,  and  the  really  successful  commercial  viticulture 
of  the  country  dates  from  its  dissemination;  and  yet  this 
grape  is  a  pure  native  fox-grape,  and  evidently  only  twice 
removed  from  the  wild  vine." 

325.  The  grape  industry. — Grapes  of  one  kind  or  another 
grow  wild  in  all  parts  of  the  United  States,  and  in  sections  of 
Canada  and  Mexico.    The  cultivated  forms,  also,  find  con- 
genial conditions  in  widely  separated  areas  of  the  continent. 
A  large  industry  has  grown  up  in  the  province  of  Ontario. 
New  York  contains  several  centers  of  note,  especially  the 
lower  Hudson  Valley,  and  the  Lake  region  in  the  central- 
western  part  of  the  state.    Extensive  vineyards  are  located 
in  Michigan,  and  in  the  Ozarks  of  Missouri  and  Arkansas. 
There  are  also  some  plantings  in  Alabama  and  Georgia. 
Those  portions  of  Ohio,  Pennsylvania,  and  New  York  border- 
ing on  Lake  Erie  have  long  been  noted  as  grape-growing 
regions  and  there  are  extensive  plantings  in  the  interior 
valleys  of  California. 

326.  Propagation,   planting,    and   care. — The    grape    is 
propagated  from  cuttings  of  ripened  wood  of  the  preceding 
summer's  growth.    These  cuttings  may  in  exceptional  cases 
consist  of  a  single  eye,  planted  in  sand  much  as  if  they  were 
seeds;  but  this  method  is  resorted  to  only  in  the  case  of  very 
valuable  plants  where  rapid  increase  in  number  is  desired. 
Ordinarily,  the  cuttings  are  from  eight  to  eighteen  inches  in 
length;  the  longer  ones  are  for  very  light  open  soil  that  is 
likely  to  dry  out  to  a  considerable  depth,  the  shorter  cuttings 
for  the  relatively  heavy  and  retentive  soils.    In  those  sections 


SMALL-FRUITS  AND   THE  GRAPE  217 

of  the  country  in  which  the  grape  root-louse  must  be  taken 
into  account,  the  grape  is  grafted  on  some  form  of  resistant 
American  stock.  The  cuttings  are  usually  rooted  in  the 
nursery,  but  sometimes  they  are  set  out  directly  in  the 
field.  Distance  of  planting  depends  on  variety  and  local 
conditions.  The  most  common  is  eight  feet  each  way. 

The  grape  comes  into  bearing  in  about  three  years.  It  is 
a  healthy  vigorous  plant,  and  will  continue  in  profitable 
production  for  many  years  if  given  careful  and  intelligent 
attention.  There  is  a  constant  struggle,  however,  between 
the  wood-growth  and  the  fruit-growth  tendencies  of  the  vine 
which  is  much  more  pronounced  than  is  the  case  with  most 
orchard  fruits.  The  only  way  by  which  this  can  be  regulated 
is  by  proper  pruning;  and  this,  therefore,  becomes  of  supreme 
importance  in  grape-growing. 

327.  Grape  pruning. — In  discussing  the  pruning  of  grapes, 
the  following  terms  are  commonly  used:  (The  letters  refer 
to  Fig.  113.) 


FIG.  113. — A  grape- vine  pruned  and  tied  by  the 
long-cane  system. 

Trunk — the  main  body  of  the  vine. 
H.     Branch — a  principal  division  of  the  trunk. 
A.     Arm — a  division  intermediate  between  branch  and  cane. 
C.     Cane — a  ripened  shoot. 

Shoot  -a  growing  leafy  branch,  the  wood  of  which  is  not  yet  matured. 
S.     Spur — a  cane  cut  back  to  a  stub  containing  one  to  four  eyes. 

Adventitious  bud — a  bud  arising  from  undifferentiated  tissue. 

Water-sprout — a  sprout  growing  from  an  adventitious  bud  above 
the  surface  of  the  ground. 

Sucker — a  similar  shoot  starting  below  the  surface. 


218  HORTICULTURE  FOR  SCHOOLS 

Since  the  primary  object  in  pruning  is  to  secure  a  maximum 
yield  of  choice  fruit,  the  first  question  which  naturally  arises 
is  where  the  bunches  of  grapes  are  found  on  the  growing  vine. 
These  bunches  are  not  borne  on  old  wood.  They  are  not  on 
shoots  which  arise  from  wood  more  than  two  years  old.  That 
is,  there  is  no  fruit  on  water-sprouts  or  suckers.  The  fruit 
occurs  on  shoots  arising  from  buds  on  canes  of  the  previous 
season's  growth.  As  a  rule,  the  first,  second,  and  third  nodes 
of  the  shoot  indicate  the  points  at  which  the  bunches  of 
grapes  will  develop,  though  sometimes  they  are  found  farther 
out. 

For  those  vines  which  bear  their  fruit  in  the  lower  nodes 
of  the  shoot,  the  method  of  pruning  used  is  called  the  spur  or 
short  system,  while  in  the  case  of  those  varieties  which  bear 
the  grapes  farther  out  on  the  shoot,  the  cane  or  long  system 
is  the  one  employed. 

328.    Spur-pruning. — For   the  European  vinifera  grape, 

Fig.  114  illustrates  the  spur  sys- 
tern.  The  arm  is  shown  attached 
to  the  trunk  of  the  vine.  At  the 
extremity  of  this  arm  are  two 
canes  A  and  B.  These  two  canes 
have,  during  the  season  just 

!$[      /JL^^SS*^       closed,  borne  fruit.     In  pruning, 
ij^^S^^^         T         one  °f  them,  usually  the  outer,  or 
t  fljfrS  A,    is    removed    entirely.     The 

FIG    114.— Unit  of  short  prun-         Other,    B,    is   CUt    back  to  tWO    Or 

three  or  four  eyes,  for  example  at 

the  point  X,  leaving  a  fruit-spur  of  one,  two,  or  three  buds. 
When  growth  starts  on  this  spur,  shoots  will  develop  from  each 
of  these  buds;  these  shoots  will  bear  fruit,  and  they  will  in  turn 
be  treated  next  year  as  A  and  B  have  been  treated  this  season. 
Year  by  year  the  fruit-bearing  portion  of  the  arm  gradually 
extends  outward  as  can  readily  be  seen.  It  is  necessary  for 
cultivation  and  other  reasons  to  keep  this  arm  shortened  to 


SMALL-FRUITS  AND   THE  GRAPE 


219 


within  reasonable  limits.  The  way  in  which  this  is  done  is 
indicated  in  the  drawing.  It  will  be  noticed  that  there  is 
another  cane  growing  from  the  point  close  to  the  lower  end 
of  the  arm,  labeled  C.  If  the  arm  becomes  too  long,  C  will 
be  allowed  to  develop  as  indicated  and  at  the  end  of  the  first 
season  of  growth  will  be  cut  back  to  the  point  R,  new  shoots 
being  secured  from  the  buds  below  R.  The  arm  can  then  be 
cut  off  at  the  point  S  and  the  portion  of  C  below  R  becomes 
a  replacing  spur.  The  purpose  of  the  latter  is  to  shorten  the 
arm. 

The  number  of  arms  on  a  vine  is  determined  by  the  variety, 
climatic  conditions,  especially  rainfall,  and  by  richness  of 
soil.  Where  conditions  are  such  as  to  induce  greater  growth, 
the  plant  can  support  more  arms.  When  conditions  are  the 
reverse,  the  number  of  arms  must  be  reduced. 

329.  Cane-prun- 
ing.— In  this  method 
the  cane  is  not  removed 
as  in  the  case  of  spur- 
pruning,  but  is  left 
either  in  its  entirety  or 
cut  back  much  longer. 
The  figure  shows  the 
method  used  (Fig.  115). 


FIG.  115. — Unit  of  long  pruning  of  the  grape. 


A  is  a  spur  which  the  year  before  was  cut  back  to  the  line 
indicated  at  V.  At  the  same  time,  cane  B  was  left  unpruned, 
meanwhile,  B  has  produced  a  number  of  laterals,  X,  4, 2.  These 
have  borne  fruit.  A  has  produced  two  canes  from  the  two  eyes 
of  the  spur.  These  two  canes  are  indicated  as  L  and  M.  This 
vine  is  now  ready  to  be  pruned.  B  will  be  entirely  removed 
along  the  line  S.  Cane  M  will  be  retained  next  year  in  exactly 
the  same  way  that  cane  B  was  kept  last  year,  being  headed 
back  at  some  point  as  indicated  by  the  drawing  at  the  point 
B.  Cane  L  will  become  a  spur  probably  with  two  eyes,  just 
as  A  was  treated  the  year  previous.  M  will  now  develop 


220  HORTICULTURE  FOR  SCHOOLS 

laterals  as  B  did,  previously,  and  L  will  develop  two  shoots 
as  A  did  in  the  previous  season. 

Next  year's  pruning  will  consist  in  removing  M  at  R  and 
the  two  canes  of  L  will  be  treated  as  are  the  two  canes 
of  A.  Thus  the  process  is  continued  year  by  year. 

330.  Phylloxera. — The  most  destructive  insect  enemy  of 
the  European  grape  (the  American  species  are  immune)  is 
the  phylloxera,  or  root-louse.     It  was  unknown  in  Europe 
until  about  1855  when  it  was  introduced  into  France  on 
stock  imported  from  America.    At  first  it  manifested  itself 
in  a  few  isolated  localities  only;  but  soon  spread  from  vine- 
yard to  vineyard  and  from  section  to  section,  until  in  the 
year  1888,  injury  directly  due  to  it  was  estimated  at  two 
billion  dollars.   The  cause  was  found  to  be  a  very  small  insect, 
which  can  be  distinguished  only  with  the  aid  of  a  hand-lens, 
and  which  burrows  into  the  tissue  of  the  root,  causing  galls  or 
excrescences  which  ultimately  kill  the  vine.    Many  remedies 
have  been  tried;  but  the  only  one  that  is  successful  is  that 
of  grafting  the  desired  variety  on  stock  of  resistant  American 
forms.     American  stock  imported  into  France  finally  re- 
established the  grape  industry  in  that  country. 

331.  Other  insects. — A  number  of  other  insects  cause 
injury  to  the  grape,  among  them,  the  vinehopper,  root-worm, 
grape-beetle,  cutworm,  grape-curculio,  sawfly,  root-lover,  and 
grape-vine  sphinx.    Each  has  been  studied  and  information 
concerning  methods  of  control  can  be  found  in  the  publica- 
tions of  the  experiment  stations. 

332.  Raisins  have  long  been  used  as  human  food.    They 
are  mentioned  several  times  in  the  Old  Testament1  and  other 
writers,  ancient  and  medieval,  bear  witness  to  their  popu- 
larity.   Until  the  development  of  the  raisin  industry  in  Cali- 
fornia within  the  last  few  years,  they  were  produced  solely 
in  a  few  countries  about  the  Mediterranean.    California  is 
now  forging  ahead  in  the  commercial  production  of  raisins. 

i  Numbers  VI-3;  I  Samuel  XX V-l 8;  XXX-12. 


SMALL-FRUITS  AND   THE  GRAPE  221 

They  are  not  dried  on  the  vine  as  is  the  case  in  countries 
where  labor  is  cheap,  but  are  picked  and  dried  on  trays.  To 
hasten  the  evaporation  process,  the  grapes  are  dipped  in 
various  solutions.  They  are  then  stacked  or  piled  to  produce 
sweating.  Stemming  and  seeding  are  done  entirely  by 
machinery. 

Efforts  to  grow  the  Sultana,  a  Smyrna  seedless  variety, 
met  with  indifferent  success.  The  variety  seems  to  revert  to 
a  seeded  form  whenever  removed  from  its  native  habitat. 
A  California  variety  has  now  been  secured,  the  Thompson's 
Seedless,  or  Sultanina.  This  has  proven  to  be  superior  to  the 
Sultana  in  almost  every  respect. 

Zante  currants,  known  also  as  English  currants,  are  in 
reality  a  type  of  raisin.  They  are  the  products  obtained  by 
drying  a  small  black  grape  called  the  Corinth,  which  grows 
in  Greece  and  some  of  the  islands  adjacent  to  it.  Efforts  have 
been  made  recently  by  the  United  States  Department  of 
Agriculture  to  introduce  this  fruit  into  the  United  States  and 
the  result  will  be  awaited  with  interest. 

EXERCISES 

EXERCISE  I. — Study  of  bearing  habits  of  various  kinds  of  berries. 

Materials. — Small  patches  of  plants  of  as  many  kinds  of  berries  as 
possible. 

Procedure. — (1)  Study  blossoms  of  as  many  kinds  of  the  small-fruits 
as  possible.  Note  their  arrangement,  size,  and  structure.  What  is  the 
age  of  the  wood  upon  which  the  blossoms  are  borne?  Are  the  flowers 
perfect  or  imperfect? 

(2)  Examine  berries  "of  as  many  bush-fruits  as  possible.  Study  their 
structure.  Note  where  they  are  borne.  State  the  relation  the  bearing 
habit  of  each  kind  of  bush-fruit  has  to  pruning. 

EXERCISE  II. — Study  of  commercial  methods  in  berry  production. 

Materials. — Berry  farms  in  your  locality. 

Procedure. — If  possible  visit  berry  farms  in  your  locality.  (1)  Make 
a  list  of  favorable  and  unfavorable  factors  present  for  the  growing  of 
the  berries.  (2)  Study  and.  report  on  the  methods  of  harvesting  and 


222  HORTICULTURE  FOR  SCHOOLS 

marketing  various  kinds  of  berries.  What  factors  enter  into  the  success- 
ful marketing  of  berries?  Suggest  if  possible,  improvements  on  the 
systems  now  in  use  in  your  locality.  (3)  Secure  as  much  data  as  possible 
on  the  following  for  a  number  of  kinds  of  berries:  (a)  Cost  of  bringing 
an  acre  of  the  plants  into  bearing;  (b)  cost  of  all  cultural  operations, 
harvesting,  marketing,  and  the  like;  (c)  yields. 

EXERCISE  III. — Project:  The  growing  of  small-fruits  is  an  excellent 
project  for  the  student,  especially  if  arrangements  can  be  made  to 
continue  the  work  for  more  than  one  season. 

EXERCISE  IV. — Grape  cuttings. 

Materials. — Canes  of  varying  lengths;   small  sharp  pruning  shears. 

Procedure. — Make  cuttings  from  canes,  being  careful  that  the  lower 
cut  is  just  below  a  bud  and  the  upper  cut  is  just  above  a  bud.  Have 
these  cuts  of  different  lengths,  from  eight  to  twenty-four  inches.  Divide 
the  cuttings  into  two  groups,  having  an  equal  number  of  each  length 
in  each  group.  Place  one  lot  in  the  ground  so  that  they  stand  perpen- 
dicular or  nearly  so  and  with  two  buds  exposed  above  the  surface. 
Leave  them  here  until  they  are  well  rooted.  Place  the  others  side  by 
side  in  a  pit  partially  filled  with  sand;  then  cover  with  sand  to  a  depth 
of  six  inches  or  one  foot  and  leave  them  until  the  ends  have  become 
callused.  After  callusing  plant  the  cuttings  in  the  ground  as  in  the  case 
of  the  other  cuttings.  Note  results  in  each  case. 

(It  is  sometimes  an  advantage  to  callus  cuttings  in  this  way  to  avoid 
drying  out.) 

EXERCISE  V. — Leaf  characteristics. 

Materials. — Leaves  from  different  varieties  of  cultivated  grapes  and 
if  possible  from  grapes  growing  wild  in  the  neighborhood. 

Procedure. — Make  drawings  of  as  many  different  leaves  as  you  have 
available,  noting  especially  the  characteristics  of  those  forms  which 
have  been  imported  from  the  Old  World  and  of  those  which  are  known 
to  be  indigenous  to  America  or  closely  related  to  native  wild  grapes. 
The  student  can  ascertain  the  probable  origin  of  the  different  varieties 
in  such  books  as  Bailey's  Standard  Cyclopedia  of  Horticulture  or  Evolu- 
tion of  Our  Native  Fruits, 

EXERCISE  VI. — If  the  student  has  a  grape  project,  he  should  prepare 
and  give  before  the  class  a  full  account  of  it,  giving  such  data  as  size 
of  project,  age  of  vine,  varieties,  methods  of  pruning,  time  of  pruning, 
cultural  treatment  at  different  seasons  of  the  year,  probable  yield, 
value  of  crop,  and  all  other  topics  concerning  which  he  has  information. 


CHAPTER  XVI 
INSECTS  AND  THEIR  CONTROL 

OF  all  the  problems  with  which  the  horticulturist  has  to 
contend,  that  of  insect  control  is  one  of  the  most  insistent 
and  baffling.  From  the  time  of  plagues  of  locusts  described 
in  the  Old  Testament  to  the  present  moment,  insect  depreda- 
tions have  not  ceased  to  be  a  menace  to  human  welfare  in 
every  country.  Sanderson  gives  some  illuminating  figures 
regarding  insect  injury  in  the  United  States.  He  says  that 
cereal  crops  probably  suffer  a  ravage  amounting  to  three 
hundred  millions  of  dollars;  hay  crops  are  injured  to  the 
extent  of  sixty-five  millions;  cotton  suffers  from  the  boll- 
worm  and  other  insects  to  the  extent  of  eighty-five  millions; 
fruits  are  diminished  in  value  fully  20  per  cent  each  year, 
making  the  total  approach  very  close  to  thirty  millions.  The 
forests  suffer  very  severely,  probably  over  one  hundred  ten 
million  dollars  annually;  live-stock  products,  three  hundred 
millions;  stored  goods  of  various  kinds,  two  hundred  mil- 
lions ;  truck  crops,  one  hundred  fifty  millions.  In  addition 
to  these,  the  injury  to  various  incidental  crops  brings  the 
total  loss  in  one  year  to  a  figure  well  over  one  billion  dollars. 
In  addition  to  these  losses  caused  by  injury,  vast  amounts  are 
spent  each  year  on  control  of  one  sort  or  another. 

333.  The  insect. — The  technical  name  of  insects  is  Hexa- 
poda.  The  word  indicates  the  basis  on  which  they  are  sepa- 
rated from  the  remainder  of  the  animal  kingdom,  for  Hexa 
means  six,  and  poda  feet.  An  insect,  therefore,  is  simply  a 
six-footed  animal.  The  spiders,  which  are  ordinarily  asso- 
ciated with  insects,  are  different  in  that  they  have  eight  feet 
instead  of  six. 

223 


224  HORTICULTURE  FOR  SCHOOLS 

The  insect  structure  is  peculiar.  The  body  is  divided  into 
three  parts,  head,  thorax,  and  abdomen.  The  skeleton,  in- 
stead of  being  a  bony  framework  within  the  body  as  is  the 
case  with  the  higher  animals,  is  a  shell-like  covering  outside 
of  the  body;  this  is  known  as  an  exo-skeleton,  from  the  Greek 
exo,  out.  Each  insect  is  provided  with  two  pairs  of  wings1 
and  a  mouth  modified  either  for  biting  or  sucking.  The 
internal  structure  is  highly  complex.  There  is  a  circulatory 
and  a  digestive  system,  and  an  arrangement  for  breathing 
that  is  wholly  unique  and  very  interesting.  This  breathing 
system  consists  of  ducts  situated  behind  and  below  the  wings, 
and  connected  by  small  tubes  with  the  outside  of  the  body. 
As  the  wings  move,  air  is  introduced  into  and  expelled  from 
these  openings,  thus  supplying  the  insect  with  the  oxygen 
necessary.  One  peculiar  fact  is  that  some  insects  may  keep 
these  openings  closed  for  a  long  period;  and  this  adds  to  the 
difficulty  of  their  control.  Beetles  left  for  days  in  an  atmos- 
phere containing  deadly  cyanide  gas  will  seem  dead  when 
taken  out,  but  frequently,  after  a  period  of  hours,  will  revive 
and  crawl  away  uninjured. 

334.  Insect  groups. — Flies  are  distinguished  by  having 
apparently  one  pair  of  wings  only.  From  this  fact  they 
derive  their  technical  name,  Diptera,  from  two  Greek  words, 
di  meaning  double,  and  ptera,  wings.  If  the  fly  is  examined 
closely,  a  pair  of  stubs  one-fourth  inch  or  less  in  length  will 
be  found  beneath  the  wings  and  attached  to  the  back.  These 
stubs  are  really  rudimentary  wings;  so  that  while  the  fly 
appears  to  have  one  pair  of  wings  only,  it  really  has  two. 
The  butterfly  and  moth  group  is  distinguished  from  others 
by  the  scale-like  covering  on  the  wings;  hence  the  name, 
Lepidoptera,  from  lepido,  a  scale.  The  group  is  subdivided 
into  two  smaller  divisions,  butterflies  and  moths.  The  former 
have  three  distinguishing  characteristics;  when  at  rest  their 
wings  remain  poised  in  the  air,  the  antennae  or  "feelers"  are 

»  There  are  some  exceptions  to  the  rule. 


INSECTS  AND   THEIR  CONTROL  225 

clubbed  at  the  end,  and  the  members  fly  in  the  daytime  only. 
Moths,  on  the  other  hand,  have  unclubbed  antennae,  fly  at 
night,  and  fold  the  wings  over  the  body  when  at  rest.  Hyme- 
noptera  include  bees  and  wasps.  Coleoptera,  which  com- 
prise beetles,  are  very  numerous  in  the  animal  kingdom, 
containing  more  individuals  and  species  than  any  other 
known  division  of  animals.  Coleoptera  are  distinguished 
by  the  existence  of  two  unlike  pairs  of  wings,  the  under 
pair  being  used  for  flight,  while  the  upper  pair  is  differ- 
entiated into  a  hard  shell-like  protective  covering.  The 
Orthoptera  constitute  one  of  the  best  known  of  all  the  insect 
divisions,  including  such  well-known  types  as  the  grass- 
hopper, katydid,  and  locust.  Historically,  this  group  was 
one  of  the  first  to  come  under  general  observation,  and  it 
has  been  one  of  the  most  baffling  as  regards  control.  Homop- 
tera  include  plant-lice,  technically  known  as  aphids,  and 
scale  insects.  Every  orchardist  has  come  into  contact  very 
intimately  with  this  last  group  for  they  are  among  the 
most  injurious  known  and  the  most  difficult  to  control. 

335.  Metamorphosis. — During  its  life  process,  the  normal 
insect  undergoes  a  number  of  changes.    As  a  rule,  it  starts 
as  an  egg,  hatches  out  into  the  larval  or  worm  form,  then 
enters  what  is  known  as  the  pupal  stage,  in  which  it  is  dor- 
mant for  a  time,  and  from  which  it  finally  emerges  a  full 
grown  or  adult  insect.    This  process  is  known  as  metamor- 
phosis.   It  is  made  clear  most  easily  by  a  study  of  one  or  two 
specific  examples. 

336.  Some  examples  of  metamorphosis. — The  butterfly 
lays  its  eggs  and  these  hatch  into  caterpillars.    The  cater- 
pillar feeds  on  vegetation  of  various  sorts,  growing  rapidly 
the  while.     Finally  it  spins  about  itself  a  cocoon  and  becomes 
what  is  generally  known  as  a  chrysalis.    It  may  remain  in 
this  form  a  few  days  or  several  months,  depending  on  cir- 
cumstances;   but  finally  it  assumes  the  adult  shape  and 
emerges  as  a  full  grown  butterfly.    The  cycle  is  then  repeated. 


226  HORTICULTURE  FOR  SCHOOLS 

There  are  no  essential  differences  in  the  case  of  the  fly  except 
that  the  forms  vary  somewhat  and  are  given  other  names. 
The  larval  form,  which  in  the  butterfly  is  known  as  the  cater- 
pillar, in  the  fly  is  called  the  maggot.  This  maggot  forms  a 
cocoon  as  in  the  case  of  the  butterfly  and  the  adult  insect 
emerges  from  it.  In  the  case  of  the  grasshopper,  the  cater- 
pillar and  chrysalis  stages  are  replaced  by  a  form  known  as 
the  nymph  which  undergoes  a  series  of  molts,  changing  form 
slightly  in  each  molt.  The  young  of  the  grasshopper  is  quite 
strikingly  different  from  the  mature  form,  especially  as  re- 
gards relative  sizes  of  head  and  body.  This  form  gradually 
changes  from  molt  to  molt  until  in  the  final  molt  the  adult 
insect  appears. 

337.  Reasons  for  metamorphosis. — The  purpose  of  this 
wonderful  series  of  transformations  is,  in  a  word,  to  tide  the 
insect  over  unfavorable  food  and  weather  conditions  and  is, 
therefore,  a  means  whereby  the  survival  of  the  species  is 
accomplished.     For  example,  in  the  winter  when  food  and 
weather  conditions  are  unfavorable,  many  insects  are  quies- 
cent in  the  egg,  and  others  in  the  pupal  form.    In  the  spring 
when  weather  and  food  supply  become  improved,  the  quies- 
cent forms  give  place  to  the  more  active  stages  of  larva  and 
adult. 

338.  Mouth-parts. — Insect  life  is  characterized  by  some 
very  complex  variations  as  regards  mouth-parts.     In  some 
insects  the  mouth  is  adapted  to  a  biting  process,  and  these 
secure  their  food  by  eating  the  leaves  and  tender  parts  of  the 
plants,  often  entirely  destroying  the  tissue.    In  other  insects, 
on  the  contrary,  as  in  the  butterfly,  the  mouth-parts  are  long 
tubes  specialized  for  sucking.    Such  insects  have  no  facilities 
for  breaking  or  tearing  the  tissue  of  the  plant,  and  so  Secure 
their  food  by  drawing  it  up  through  this  tube.     Some  of 
them,  like  the  butterflies,  suck  the  nectar  from  flowers;  others, 
such  as  the  aphis  and  scale  insects,  pierce  the  tissue  of  the 
plant  and  extract  the  juices  from  it. 


INSECTS  AND   THEIR  CONTROL  227 

•  This  difference  as  regards  method  of  securing  food  has  a 
very  intimate  relation  to  the  whole  question  of  insect  control. 
In  the  case  of  insects  with  biting  mouths,  it  is  possible  to  kill 
them  by  placing  poison  on  the  surface  of  the  plant ;  for  they 
eat  the  leaves  and  tender  parts  of  the  plant  in  their  entirety. 
Many  of  the  leaf -eating  beetles  and  other  insects  of  this  type 
are  controlled  entirely  in  this  way.  When  insects  subsist  by 
sucking,  this  poison  method  is,  of  course,  of  no  avail.  Since 
the  insect  does  not  eat  any  of  the  surface  tissue  of  the  plant, 
other  means  have  to  be  resorted  to.  The  so-called  contact 
sprays  which  kill  because  of  their  action  on  the  body  of  the 
insect  are  employed  here. 

The  active  agent  in  most  contact  sprays  is  kerosene  or 
distillate.  It  is,  of  course,  entirely  out  of  the  question  to 
apply  these  agents  in  undiluted  form,  as  they  would  kill 
any  plant  with  which  they  come  in  contact,  to  say  nothing 
of  the  expense  of  such  a  procedure.  It  is  also  impossible,  as 
is  well  known,  to  mix  them  with  water.  However,  by  first 
stirring  them  vigorously  with  soap,  and  then  adding  this 
soap  to  water,  there  is  formed  what  is  known  as  an  emulsion. 
The  oil  exists  in  a  very  finely  divided  condition  throughout 
the  liquid,  very  much  in  the  same  way  that  small  particles 
of  butter-fat  are  present  in  newly-drawn  milk.  In  this  form 
the  oil  is  not  injurious  to  the  tree,  and  is  sufficiently  strong  to 
kill  the  insect.  Great  care  has  to  be  exercised  in  applying 
these  emulsions  to  plants  with  tender  foliage.  They  are 
usually  applied  in  the  dormant  season  and  if  it  is  necessary 
to  use  them  on  evergreen  trees  they  are  diluted  to  such  an 
extent  as  to  minimize  the  possibility  of  injury. 

In  the  case  of  citrus  trees  in  southern  and  central  Cali- 
fornia, a  very  effective  method,  known  as  fumigation,  has 
been  perfected.  In  this  process  trees  are  covered  with  canvas 
tents,  and  a  definite  quantity  of  hydrocyanic  acid  gas  is  then 
introduced  into  these  tents.  The  gas  is  very  deadly,  and  the 
method  is  exceedingly  effective  for  the  control  of  scale  and 


228  HORTICULTURE  FOR  SCHOOLS 

insect  pests.  It  is,  however,  not  adapted  to  the  control  of 
those  insects  which  have  the  ability  to  move  about.  Fur- 
thermore, because  of  the  deadly  nature  of  the  gas,  its  use  is 
always  attended  with  danger,  and  should  not  be  undertaken 
by  a  person  who  is  not  familiar  with  it.  The  gas  is  obtained 
by  treating  sodium  cyanide  with  sulfuric  acid,  when  a  chem- 
ical reaction  takes  place  in  which  hydrogen  cyanide  is  liber- 
ated into  the  air. 

339.  Importance  of  a  study  of  life  history. — A  complete 
account  of  the  metamorphosis  of  any  given  insect,  the  condi- 
tions under  which  the  changes  take  place,  times  of  year  at 
which  they  occur,  food  on  which  the  insect  lives  during  the 


FIG.  116. — The  codlin-moth,  showing  stages  in  life  history,     a,  egg;  b,  larva;  c,  pupa; 
d,  adult.     (Greatly  magnified.) 

different  stages  and  all  other  matters  connected  with  these 
changes  is  known  as  the  life  history  of  the  insect.  A  knowl- 
edge of  this  history  is  the  first  essential  in  devising  methods 
of  control,  for  such  a  study  reveals  the  insect's  weakest  point 
and  this  suggests  the  method  of  attack  most  likely  to  result 
in  effectual  control. 

An  interesting  case  in  this  connection  is  that  of  the  codlin- 
moth  (Fig.  116).  The  larva  of  this  moth  leaves  the  fruit  in 
the  fall  and  spins  a  cocoon  in  which  it  lives  during  the  winter. 
These  cocoons  are  commonly  found  underneath  loose  scales 
or  bark  of  the  trees  where  the  larvae  have  been  feeding.  In 
the  spring  of  the  year,  about  the  time  that  active  growth 
begins  again,  these  larvse  pupate  in  the  same  cocoons  in 
which  they  spent  the  winter.  After  two  or  three  weeks  as 


INSECTS  AND   THEIR  CONTROL  229 

pupae,  the  adult  moths  emerge  and  deposit  their  eggs  on  the 
leaves  of  the  apple  or  pear  and  occasionally  on  the  newly 
formed  fruits.  The  young  insects  hatch  from  these  eggs,  eat 
into  the  fruit  and  remain  there  in  the  larval  form  until  fully 
grown.  This  requires  about  three  weeks.  They  then  leave 
the  fruit,  pupate,  and  change  into  the  moth  stage. 

Eggs  for  the  second  brood  are  now  laid  and  the  larvae  go 
through  the  same  cycle  as  did  the  first.  In  those  regions 
where  there  are  only  two  broods  in  the  year,  the  larvae  of 
this  second  brood  live  through  the  winter  as  already  described. 
In  some  of  the  apple-growing  sections  of  the  United  States, 
where  the  season  is  long,  a  third  brood  may  develop  in  the 
summer  or  early  fall. 

In  this  entire  cycle,  there  is  just  one  vulnerable  point. 
This  is  the  point  at  which  the  young  larva  starts  to  enter  the 
apple.  The  egg  hatches  just  about  the  time  the  petals  drop 
in  the  spring.  Very  soon  after  that  the  young  larva  crawls  to 
the  blossom-end  of  the  apple,  and  there  enters  through  the 
calyx-tube.  It  must  eat  its  way  in  to  gain  access  to  the  in- 
terior of  the  fruit.  This  is  the  point  at  which  it  can  be  caught. 
A  poison  spray  applied  to  the  apple  in  such  a  way  as  to  cover 
the  open  calyx  end  will  kill  practically  all  of  the  young  worms. 
To  do  this,  however,  it  is  necessary  that  the  spray  be  applied 
before  the  calyx-tube  closes.  If  the  spraying  is  delayed  too 
long,  it  is  impossible  to  get  the  poison  material  inside  the 
closed  calyx-tube,  the  insect  finds  its  way  between  the  sepals 
of  the  calyx-tube,  and  thence  eats  into  the  apple,  without 
coming  in  contact  with  any  of  the  poison.  A  spray  delayed 
two  weeks  may,  therefore,  be  entirely  ineffectual;  but  if  the 
material  is  applied  at  just  the  correct  time,  the  number  of 
apples  infested  with  worms  will  be  very  small  indeed. 

340.  Control. — The  codlin-moth  is  controlled  by  spraying 
with  some  arsenical  poison,  the  most  common  of  which  is 
arsenate  of  lead.  This  material  is  applied  at  the  strength  of 
three  pounds  of  paste  or  one  and  one-half  pounds  of  powdered 


230  HORTICULTURE  FOR  SCHOOLS 

arsenate  of  lead  to  one  hundred  gallons  of  water,  just  after 
the  blossoms  drop  and  before  the  calyx-lobes  have  closed 
over  the  end  of  the  little  apple. 

In  cases  in  which  there  is  a  bad  infestation  in  the  orchard, 
more  than  one  spray  must  be  used.  Usually  two  at  least  are 
necessary,  the  second  being  applied  from  two  to  three  weeks 
after  the  first.  Later  spraying  must  be  timed  by  the  egg- 
laying  of  the  moths  or  the  occurrence  of  the  little  larvae  just 
hatched  from  the  eggs.  Thoroughness  in  the  application  of 
the  spray  is  the  most  important  factor  in  successful  control. 
341.  Borers  (Figs.  117-118). — Much  damage  sometimes 
results  to  fruit-trees  from  the  attack  of  borers.  Of  the 

numerous  species,  the  flat-headed 
borer  is  the  one  most  commonly  seen . 
East  of  the  Rocky  Mountains,  a  spe- 
FIG.  ii7.— La^TcJ  flat-headed  cies  of  beetle  known  as  the  round- 
headed  borer  occurs  commonly. 

The  flat-headed  borer  in  its  mature  state  is  a  little  dark 
colored  beetle,  with  metallic  reflections.  But  it  is  the  larval 
form  that  is  of  chief  concern.  This  larva  has  a  small  head  and 
a  tapering  body.  Just  back  of  the  head 
is  a  greatly  enlarged  segment  which 
looks  to  the  casual  observer  as  if  it 
were  a  part  of  the  head.  Because  of 
this  enlarged  segment,  the  insect  has 
the  name  of  the  flat-headed  borer.  FlG.  ii8.— Adults  flat-headed 

The  mature  insect  deposits  its  eggs 

on  the  bark  of  the  tree.  From  the  egg  hatches  the  larva  just 
described.  This  larva  feeds  at  first  just  beneath  the  bark 
of  the  infested  tree.  Sometimes  it  completely  girdles  the 
tree.  After  feeding  for  a  time,  it  begins  to  burrow  into  the 
heart-wood.  The  burrow  is  of  a  characteristic  oval  shape  and 
thus  may  be  distinguished  from  that  of  the  round-headed 
borer  which  is  circular  in  cross-section. 

The  adult  of    the  round-headed  species  is  a  beautiful 


INSECTS  AND   THEIR  CONTROL  231 

brown  beetle  with  long  antennae  and  white  stripes  on  the 
wing-covers.  The  larvae  somewhat  closely  resemble  those 
of  the  flat-headed  borers  but  are  more  circular  in  outline. 
The  injury  is  quite  similar.  In  the  case  of  this  species,  how- 
ever, it  takes  three  years  for  the  larvae  to  undergo  all  the 
different  stages  of  their  development  and  change  into  the 
adult. 

In  addition  to  these  two  types,  the  shot-hole  borer  is  com- 
mon in  fruit-growing  regions  both  of  the  East  and  the  West. 
The  adult  is  a  tiny  brown  beetle  which  lays  its  eggs  in  the 
bark  of  fruit-trees,  where  the  larvae  hatch  and  begin  to  con- 
struct their  characteristic  burrows  beneath  the  surface.  Trees 
which  are  infested  always  have  small  holes  resembling  shot- 
holes  in  the  bark.  It  is  from  this  fact  that  the  name  of  the 
insect  is  derived. 

In  the  case  of  all  these  different  boring  insects,  injury  is 
greatest  in  case  of  weakened  trees.  Sun-scalded  trunks  or 
branches  are  nearly  always  attacked  by  one  or  the  other  of 
these  borers.  It  is  of  utmost  importance,  therefore,  that 
young  trees  be  kept  in  active  vigorous  condition,  and  that 
the  bark  of  the  young  tender  trunks  be  protected  from  the 
sun.  The  beetles  of  the  shot-hole  species  breed  in  dead  wood, 
either  when  on  the  trees  or  when  piled  in  the  orchard,  a  fact 
to  be  remembered  in  planning  the  work  of  control. 

Another  boring  insect  commonly  seen  in  the  orchard  is 
the  termite  or,  as  it  is  commonly  called,  the  white  ant. 
This  is  usually  a  little  white,  yellowish,  or  sometimes  dark 
colored  insect,  resembling  an  ant.  Entrance  to  the  tree  is 
frequently  gained  through  a  crown-gall  which  protrudes 
above  the  surface  of  the  ground  and  where  more  or  less  decay 
is  taking  place.  Like  the  other  borers,  the  termites  rarely 
attack  a  quite  healthy  tree. 

342.  Apple-tree  leaf -roller. — From  time  to  time,  the  pest 
known  as  the  apple-tree  leaf -roller  becomes  very  troublesome 
in  the  orchard,  injuring  both  the  fruit  and  the  foliage.  The 


232  HORTICULTURE  FOR  SCHOOLS 

injury  to  the  fruit  consists  of  scabbing  and  distortion  because 
of  portions  eaten  away  by  the  larva. 

The  adult  is  a  little  moth  having  a  wing  expanse  of  about 
five-eighths  of  an  inch  to  1  inch.  It  is  rusty  brown  in  color 
with  more  or  less  lighter  brown  or  white  markings  on  the 
wings.  The  eggs  are  laid  on  the  bark  of  the  fruit-trees  in  the 
summer.  These  may  be  found  in  little  masses  of  ten  to  one 
hundred  fifty  eggs  covered  with  a  protective  varnish-like 
secretion.  In  shape  the  clusters  are  more  or  less  oval  or 
circular,  the  greater  length  being  about  three-sixteenths  of  an 
inch  and  the  lesser  about  one-eighth  of  an  inch. 

Hatching  is  in  the  spring  just  after  the  buds  begin  to  burst 
open.  The  period  of  hatching  is  somewhat  long  and  larvae 
may  be  emerging  from  the  eggs  in  the  same  mass  for  two 
weeks  or  more.  Immediately  after  hatching,  the  larvae  seek 
as  a  feeding  place  the  unfolded  buds,  which  are  often  injured 
to  the  extent  that  they  drop  from  the  trees.  The  larva  spins 
a  web  about  the  leaves  in  the  bud,  sometimes  preventing 
unfolding.  When  fully  grown  or  after  feeding  for  about  three 
weeks,  the  larvae  pupate,  usually  on  the  foliage,  changing  to 
the  moth  stage  in  about  two  weeks.  The  moth  then  lays 
eggs,  and  the  life  cycle  begins  again.  There  is  only  one  brood 
of  the  insect  during  the  season. 

Control  is  best  accomplished  by  a  very  thorough  applica- 
tion of  miscible  oil.  This  material  can  be  purchased  in  the 
market  and  requires  only  dilution  with  water  before  being 
applied.  This  should  be  done  at  the  rate  of  one  gallon  of  the 
spray  material  to  fifteen  gallons  of  water. 

343 .  Canker-worms. — Fruit-trees  are  frequently  attacked 
by  canker-worms,  of  which  there  are  two  species,  the  spring 
and  the  fall  canker-worm.  The  eggs  of  the  spring  insect 
are  deposited  during  the  months  of  March  and  April,  hatch- 
ing shortly  after  growth  of  the  trees  begins,  the  larvae  feeding 
on  the  foliage.  The  eggs  of  the  fall  species  are  laid  about 
August  or  September,  the  winter  season  being  spent  in  this 


INSECTS  AND  THEIR  CONTROL  233 

stage.  The  larvae  are  quite  variable  in  color,  some  of  them 
being  green,  others  brown  and  still  others  almost  black. 
They  are  quite  slender  and,  when  full  grown,  are  practically 
one  inch  long. 

These  canker-worm  larvae  are  very  often  called  measuring 
worms  because  of  their  peculiar  looping  way  of  traveling. 
They  have  two  sets  of  legs,  the  forward  set  being  called 
prolegs.  The  two  species  differ  in  the  number  of  these  pro- 
legs;  the  spring  insect  has  two  pair,  while  the  fall  species  has 
three. 

Control  is  best  brought  about  by  the  application  of  arsenate 
of  lead  while  the  larvae  are  quite  small.  Nicotine-sulfate 
has  also  been  used  successfully,  especially  at  the  time  when 
the  larvae  are  not  more  than  half  grown.  When  they  become 
adult,  they  may  devour  large  quantities  of  spray-covered 
foliage,  without  being  killed. 

The  female  moths  of  both  species  are  wingless  and  herein 
differ  markedly  from  most  other  moths.  Because  of  this  fact, 
control  has  been  accomplished  by  the  placing  of  sticky  tangle- 
foot or  some  other  kind  of  band  around  the  trunks  of  trees 
to  prevent  the  female  moths  from  climbing  up  to  deposit  their 


la 
th 

T: 


344.  Red-humped  caterpillar. — Frequently  fruit-trees  are 
infested  by  a  larva  which  is  characterized  by  a  red  head  and 
red  hump  bearing  black  spines.  This  hump  is  on  the  first 
abdominal  segment.  The  abdomen  bears  stripes  which  are 
also  quite 'characteristic  of  the  species.  This  larva,  because  of 
its  appearance,  is  called  the  red-humped  caterpillar. 

The  adult  of  the  insect  is  a  brown  or  grayish  moth.  It 
lays  its  eggs  on  the  leaves  of  the  host  plant  where  they  hatch, 
the  larvae  afterwards  feeding  gregariously,  that  is,  in  clusters, 
'he  winter  season  is  spent  in  the  pupal  stage,  the  moths 
issuing  from  the  pupa  cases  in  the  spring,  to  deposit  their 
eggs. 

Control  may  be  brought  about  by  removing  the  clusters  of 


234  HORTICULTURE  FOR  SCHOOLS 

larvse  from  the  infested  trees.  This  is  done  by  cutting  the 
branch  on  which  they  are  feeding.  Since  this  insect  devours 
the  foliage,  a  poison  spray  such  as  arsenate  of  lead  or  paris 
green  can  be  used  effectively  in  its  control.  It  does  not, 
however,  usually  become  serious  enough  so  that  spraying  is 
necessary. 

345.  Tent-caterpillar. — There  are  two  species  of  tent- 
caterpillars.    One  is  commonly  known  as  the  eastern  apple- 
tree  tent-caterpillar,  the  other  as  the  western  apple-tree  tent- 
caterpillar.    The  adult  moths  as  well  as  the  other  stages  of 
the  two  insects  are  very  similar  in  appearance.    The  brown 
moths  are  distinguished  by  two  white  bands  on  the  wings. 
They  have  a  wing  expanse  of  about  one  and  one-half  inches 
or  less.    The  larvae  are  covered  with  a  dense  mass  of  hairs. 
In  color,  they  are  black  or  yellow  with  white  stripes  and  blue 
or  white  dots  on  the  side.    In  length,  the  adult  larva  is  about 
one  and  three-fourths  inches. 

The  eastern  species  constructs  a  large  web  nest  which  may 
be  commonly  seen  in  cherry  as  well  as  apple  trees.  The  eggs 
of  both  species  are  laid  in  a  mass  encircling  a  small  twig  of  the 
host  plant.  The  winter  season  is  spent  in  this  stage. 

Control  of  either  species  may  be  accomplished  by  the  re- 
moval of  the  infested  twigs  or  by  a  thorough  application  of 
an  arsenical  spray,  preferably  arsenate  of  lead. 

346.  Fall  webworms. — Like  the  tent-caterpillars,  the  fall 
webworms  of  the  East  and  of  the  coastal  region  of  the  West 
are  different.    In  each  case,  the  adult  moth  has  snowy  white 
wings  with  an  expanse  of  about  one  and  one-half  inches. 
The  eastern  species  differs  from  the  western  in  having  a 
spotted  abdomen.    The  female  moth  of  each  deposits  from 
four  to  five  hundred  eggs  on  the  leaves  of  the  trees.    These 
leaves  serve  as  food  for  the  larvse.    The  larvse  are  gregarious 
in  their  feeding  habits  and  large  colonies  may  be  found  in 
web  nests  spun  about  small  branches  of  the  tree. 

The  winter  season  is  spent  in  the  soil  or  on  the  trunks  of 


INSECTS  AND  THEIR  CONTROL 


235 


trees  in  the  pupal  stage.  Control  may  be  effectively  accom- 
plished by  the  removal  of  the  web  nests  containing  the  larvae, 
especially  in  cool  weather  or  at  night  when  all  the  larvae  are 
within  the  nest,  or  by  spraying  with  arsenate  of  lead  or  some 
other  good  arsenical  spray. 

347.    Plum  curculio  (Fig.  119). — A  very  common  and  se- 
rious pest  east  of  the  Rocky  Mountains,  both  of  the  stone- 


FIG.  119. — The  plum  curculio.    a,  larva  in  fruit;  6,  fruit 
punctured  by  beetle;  c,  larva  and  pupa;   d,  adults. 

and  pome-fruits,  is  the  plum  curculio.    It  does  not  occur  in 
any  of  the  fruit-growing  regions  west  of  the  rockies. 

The  adult  is  one  of  the  so-called  snout  beetles.  These  are 
distinguished  from  other  Coleoptera  by  the  head  being  pro- 
longed into  a  beak  which  is  often  as  long  as  the  remainder  of 
the  body.  The  beetle  punctures  the  skin  of  the  apple,  peach, 
plum,  or  other  fruit,  depositing  its  eggs  just  beneath  the  surface 


236 


HORTICULTURE  FOR  SCHOOLS 


and  forming,  wherever  an  egg  is  laid,  a  little  crescent-shaped 
mark.  The  egg  hatches  into  a  little  footless  larva  or  grub, 
whitish  in  color  and  about  one-third  of  an  inch  long.  This 
larva  feeds  in  the  fruit  until  fully  grown,  when  it  transforms 
into  the  pupal  stage,  later  developing  into  the  adult  beetle. 
The  insect  hibernates  as  an  adult  in  rubbish  near  trees  where 
it  feeds.  In  the  early  spring  when  the  buds  are  unfolding,  more 


FIG.  120. — The  plum  gouger  and  its  work,  showing  injured 
blossoms  and  fruits,  larva  and  adult. 

or  less  feeding  is  done  by  the  beetles  on  the  tender  tissues  of 
the  leaves.  One  female  lays  from  one  to  three  hundred  eggs. 
Control  of  this  pest  is  best  accomplished  by  means  of  an 
arsenical  spray  which  must  be  used  at  least  three  times  in 
the  season.  The  first  application  for  codlin-moth  or  apple- 
worm  also  serves  to  destroy  large  numbers  of  the  adult  plum 
curculio  beetles.  A  spray  three  weeks  later,  which  is  also 


INSECTS  AND   THEIR  CONTROL  237 

about  the  time  for  second  application  for  the  codlin-moth, 
is  valuable  in  the  control  of  the  curculio  and  a  third  spray 
two  weeks  later  should  be  made  if  serious  injury  is  feared. 

348.  Plum  gouger  (Fig.  120)  is  another  snout  beetle, 
closely  resembling  the  plum  curculio.    Its  native  habitat  is 
the  wild  plum  of  the  Mississippi  Valley  and  Rocky  Mountain 
regions.    The  injury  to  the  plum  is  somewhat  similar  to  that 
inflicted  by  the  curculio. 

The  adult  beetle  differs  in  having  no  humps  on  the  whig- 
covers  such  as  those  which  occur  on.  the  plum  curculio,  and 
it  is  also  characterized  by  a  longer  snout.  The  beetle  hiber- 
nates during  the  winter,  coming  out  in  the  spring  when  plum 
trees  are  in  bloom,  and  first  feeds  in  the  blossoms.  The  small 
plums  as  they  are  forming  are  punctured  by  the  snout  of  the 
beetle  and  eggs  are  laid  within  the  puncture.  The  larva  feeds 
principally  inside  of  the  pit  of  the  plum  as  it  develops. 

Control  by  means  of  a  spray  of  arsenate  of  lead  at  the 
strength    of    three 
pounds  to  fifty  gal- 
lons of  water  may  be 

effective.  Fio.  121.— Scale  insects  —  three  mature  Citricola  and 

349.  Scale  insects          one  black  scale. 

(Fig.  121). — No  pests  on  trees  and  shrubs  do  more  injury 
than  the  scales.  These  are  all  tiny  sucking  insects  which 
puncture  the  tissues  of  a  plant  with  mouth-parts  which 
are  adapted  to  sucking  and  which  pump  the  sap  from  with- 
in. Two  general  types  are  recognized  by  the  entomologists. 
One  is  known  as  the  armored  scale  and  the  other  as  the 
lecanium  scale.  The  former  secretes  a  scale  which  forms 
a  protective  covering  separate  from  the  body  of  the  in- 
sect under  which  it  lives.  The  lecanium  type  of  scale 
is  protected  by  a  hard  shell  which  is  not  separated  from  its 
body.  San  Jose  scale  is  a  good  example  of  the  armored  type. 
The  black  scale  of  California  and  the  hemispherical  scale  of 
the  East  are  instances  of  the  lecanium  type. 


238  HORTICULTURE  FOR  SCHOOLS 

350.  San  Jose  scale. — If  the  twigs  or  even  the  larger 
limbs  and  trunks  of  a  tree  infested  by  San  Jose  scale  are 
examined  in  the  winter,  little  black  or  gray  scales  varying  in 
size  from  almost  microscopic  to  about  one-sixteenth  of  an 
inch  in  diameter  may  be  seen.    By  raising  one  of  these  scales 
with  the  point  of  a  knife,  the  little  yellow  body  of  the  insect 
may  be  discovered  underneath. 

While  there  is  an  egg  stage  of  this  insect,  the  eggs  are  not 
laid  but  hatch  within  the  body,  and  the  young  are  born  alive. 
At  first  they  have  the  ability  to  travel  about  over  the  tree 
by  means  of  six  little  legs.  In  a  very  short  time,  however, 
they  become  attached  to  foliage,  fruit,  or  twigs  by  means  of 
their  beaks.  The  legs  disappear  and  the  power  of  locomotion 
is  lost.  Throughout  the  remainder  of  the  life  of  the  female 
insect,  no  movement  from  one  place  to  another  occurs.  In 
the  case  of  males,  wings  are  developed  which  enable  them 
to  fly  for  some  little  distance. 

Control  of  the  armored  scales  is  usually  by  means  of  a 
thorough  application  of  lime-sulfur  spray  at  the  strength  of 
1  gallon  of  lime-sulfur  to  10  gallons  of  water,  or  by  using  some 
form  of  oil  emulsion  spray.  In  California,  where  the  black 
scale  is  a  serious  pest  of  citrus  trees,  fumigation  with  hydro- 
cyanic acid  gas  introduced  under  a  tent  placed  over  the  tree 
is  the  remedy. 

Many  insects  have  natural  enemies  which  tend  to  keep 
them  in  check.  The  eggs  of  a  parasitic  insect  are  shown 
in  Fig.  122,  attached  to  a  larva.  These  eggs  will  hatch 
and  in  the  course  of  time  will  destroy  the  host.  The  pre- 
daceous  insects,  some  of  which  are  shown  in  Fig.  123, 
devour  aphids  and  scale  insects  and  other  forms,  and 
thereby  assist  greatly  in  the  work  of  control. 

351.  Plant-lice  (Fig.  124). — There  is  scarcely  a  plant  that 
is  not  attacked  by  one  or  more  species  of  little  soft-bodied 
insects  called  plant-lice  or  aphids.    They  derive  their  nour- 
ishment from  the  plants  by  sucking  it  from  the  tissues  through 


INSECTS  AND   THEIR  CONTROL 


239 


beak-like  mouth-parts.  Some  of  the  worst  pests  of  orchards 
belong  to  this  group.  Plants  that  are  attacked  by  the  aphids 
are  very  often  covered  with  ants,  the  reason  being  that  ants 
are  very  fond  of  the  honey-dew  which  the  plant-lice  excrete. 
Ants  have  been  known  to  care  for  certain  species  of  aphids 
during  the  winter,  taking 
them  into  their  nests  and 
placing  them  on  their  host 
plants  in  the  spring. 

The  method  of  repro- 
duction among  this  group 
of  insects  is  unusual  and 
interesting.  Many  of  them  Fl0'  122"~A  Parasitized  larva- 

spend  the  winter  in  the  egg  stage.  In  other  seasons  of  the 
year  there  is  no  egg  stage  and  reproduction  takes  place 
viviparously ;  that  is,  living  young  are  produced  without  any 

egg  stage.  Generation 
after  generation  of  these 
lice  are  produced  on 
plants  during  the  active 
growing  season  and 
some  species  continue 
feeding  throughout  the 

€1  HS&\  winter  months. 

y|  ||&  The  life  history  of  the 

'h^^^         Sh       common    woolly  aphis 


of  the  apple  is  char- 
acteristic of  the  mem- 
bers of  the  entire  group 
and  is  as  follows :  Dur- 
ing the  summer  time, 
twigs,  foliage,  and  roots 
of  apple  trees  may  be 
abundantly  infested  with  this  little  woolly  coated  insect 
which  feeds  by  means  of  a  beak  inserted  into  the  leaf  or  the 


FIG.  123.— a,  The  Eyed  Ladybird  and  b,  Ash- 
Gray  Ladybird,  predaceous  on  aphids;  c, 
the  Black  Ladybird  predaceous  on  black  scale; 
d ,  the  Mealy  Bug  destroyer. 


240 


HORTICULTURE  FOR  SCHOOLS 


FIG.  124. — Aphids  or  plant-lice. 


twig.  When  feeding  first  begins  in  the  spring  of  the  year,  it 
will  be  noticed  that  all  the  lice  are  wingless.  This  is  also 
true  throughout  the  summer.  Early  in  the  fall,  however,  a 
'generation  develops  wings  and  has  the  ability  to  fly  from  one 
tree  or  one  plant  to  another. 

For  years  it  was  not  known  where  these  winged  lice  went 

after  flying  away  from  the 
apple.  It  was  finally  dis- 
covered by  Edith  M.  Patch, 
entomologist  of  the  state 
of  Maine,  that  the  elm  tree 
serves  as  an  intermediate 
host  for  this  pest.  When 
the  lice  developed  wings, 
they  flew  from  the  apple  to 
the  elm  and  there  pro- 
duced viviparously  sexual  forms  of  the  species,  the  female  of 
which  was  found  to  deposit  one  egg  on  the  bark  of  the  elm. 
There  hatched  from  this  egg  a  louse  which  fed  for  a  time  on 
the  elm,  but  the  succeeding  generation, 
attaining  wings,  migrated  back  to  the 
apple.  All  species  of  plant-lice  do  not 
follow  this  peculiar  custom  in  their 
migration,  but  nevertheless  it  is  quite 
characteristic  of  the  group. 

Control  of  all  species  can  be  accom- 
plished by  very  thorough  spraying  with 
nicotine  sulfate  (Black  leaf  40)  and  soap, 
using  the  nicotine  sulfate  at  the  strength     FlQ"  125— ^d-sPider. 
of  one  part  to  1000  parts  of  water  and  about  three  pounds 
of  whale  oil  soap  to    two  hundred  gallons  of  the  diluted 
rspray.    Thoroughness  in  the  application  of  the  liquid  is 
exceedingly  important. 

Nicotine  sulfate  is  a  poison  which  must  come  in  actual 
contact  with  the  insect  before  it  will  kill;   therefore,  in  the 


INSECTS  AND   THEIR  CONTROL  241 

work  of  spraying  for  the  control  of  any  of  the  plant-lice,  the 
greatest  care  must  be  exercised  in  order  that  practically  all 
of  the  lice  receive  an  application  of  the  spray. 

352.  Mites. — Under  the  term  "mites"  is  included  a  num- 
ber of  the  so-called  red-spiders  (Fig.  125).  These  often  do 
considerable  injury  to  the  foliage  of  fruit-trees  and  other 
plants.  Three  species  are  common.  These  are  known  as  the 
brown  or  clover  or  almond  mite,  the  two-spotted  mite,  and 
the  citrus  mite.  Of  the  three  species,  the  two  most  commonly 
seen  are  the  brown  and  the  two-spotted  mite.  The  former 
may  be  found  during  the  winter  season  in  the  egg  stage,  the 
eggs  being  deposited  about  the  buds  or  in  the  crotches  of 
deciduous  fruit-trees.  They  are  tiny  red  objects  of  a  glassy 
appearance  which  remain  unhatched  until  warm  weather 
comes  in  the  spring.  As  soon  as  the  buds  begin  to  unfold, 
the  tiny  red  mites  hatch  from  the  eggs  and  begin  to  feed. 

The  citrus  red-spider  also  spends  the  winter  in  the  egg 
stage  on  deciduous  fruit-trees.  There  might  be  more  or  less 
confusion  as  to  which  species  was  present,  in  the  mind  of  one 
who  is  untrained  in  entomology,  but  the  eggs  may  be  differ- 
entiated by  the  following  character :  In  the  case  of  the  citrus 
species,  the  egg  is  more  or  less  flattened  at  the  poles  and  bears 
a  short  stem  on  the  upper  surface  to  which  are  sometimes 
attached  fine  threads  that  anchor  it  to  the  leaf.  These  are 
absent  in  the  case  of  the  spherical  shaped  brown  mite  egg. 
The  two-spotted  mites  differ  from  the  other  two  species  in 
their  hibernating  habits,  as  they  may  be  found  during  the 
winter  in  the  soil  about  fruit-trees.  The  early  injury  to 
fruit-trees  which  takes  place  is  almost  sure  to  be  that  of  the 
brown  mite,  while  about  midsummer,  June  or  July,  when  the 
weather  becomes  hot,  the  two-spotted  mite  frequently  be- 
comes very  abundant. 

This  two-spotted  mite  is  a  web-spinning  form  and,  wherever 
prevalent,  the  foliage  of  infested  trees  is  covered  with  a  fine 
gauze.  There  is  no  web  present  when  brown  mite  is  the 


242        HORTICULTURE  FOR  SCHOOLS 

attacking  species.  The  citrus  red-spider  is  also  a  web-spinner 
and  is  found  commonly  on  citrus  trees,  but  occurs  as  well  on 
pears,  apples,  peaches,  and  certain  other  kinds  of  deciduous 
fruit-trees. 

During  the  summer  time,  the  eggs  of  both  the  citrus  red- 
spider  and  the  two-spotted  mite  may  be  found  on  the  surface 
of  infested  foliage.  The  eggs  of  the  former  are  red  in  color 
as  are  also  those  of  the  brown  mites,  while  the  eggs  of  the 
two-spotted  mite  are  white  and  appear  as  little  pearl-like 
objects,  very  inconspicuous  on  the  surface  of  the  leaf. 

353.  Control  of  mites. — In  the  case  of  brown  mite  and 
citrus  red-spider,  each  of  which  spends  the  winter  in  the  egg 
stage,  control  may  be  effected  by  treating  thoroughly  with 
lime-sulfur  at  the  strength  of  one  gallon  of  the  liquid  to  ten 
gallons  of  water  in  the  early  spring  as  the  buds  are  swelling 
on  the  deciduous  fruit-trees.    In  the  case  of  the  two-spotted 
mite,  which  does  not  spend  the  winter  season  in  the  egg  stage, 
this  treatment  would  be  of  no  avail.    As  a  substitute  for 
lime-sulfur,  any  of  the  oil  emulsions  may  be  used,  application 
being  made  at  the  same  time  as  with  the  former. 

During  the  summer,  when  active  feeding  is  taking  place, 
control  may  be  effected  by  an  application  of  sulfur  in  some 
form.  Atomic  sulfur  is  now  very  commonly  and  very  suc- 
cessfully used  in  red-spider  control.  Since  all  species  are 
killed  by  sulfur,  this  may  be  considered  the  standard  remedy. 

354.  Blister-mites. — In  addition  to  the   so-called   red- 
spiders,  a  group  known  as  blister-mites  affect  some  fruit- 
trees.    The  most  common  species,  one  which  is  distributed 
widely  through  the  different  states  of  the  Union,  is  the  pear- 
leaf  blister-mite. 

This  little  pest  winters  beneath  the  scales  of  pear  buds, 
crawling  out  when  the  buds  begin  to  unfold  in  the  spring,  and 
begins  to  feed  just  as  soon  as  growth  appears.  There  is  a 
characteristic  reddish-colored  blister-like  patch  which  forms 
wherever  this  mite  attacks  the  foliage.  Feeding  takes  place 


INSECTS  AND   THEIR  CONTROL  243 

within  the  tissues  of  the  leaf  and  injury  is  sometimes  severe. 
This  injury  is  not  confined  to  the  foliage  but  also  extends  to 
the  fruit,  causing  scabbing  and  more  or  less  distortion. 

The  control  of  this  species  is  best  accomplished  by  a 
thorough  application  of  lime-sulfur  as  recommended  for  the 
brown  mite  and  citrus  red-spider.  Treatment  should  be 
given  just  as  the  buds  begin  to  swell  in  the  spring. 

In  addition  to  the  pear  blister-mite,  several  other  species 
are  of  economic  importance.  Two  in  particular  should  be 
mentioned,  the  life  histories  of  which  are  similar  to  that  of 
the  pear-leaf  blister-mite.  These  are  the  walnut  blister-mite 
which  attacks  both  English  and  black  walnuts,  and  the 
grape-vine  blister-mite  which  causes  a  condition  commonly 
known  as  erinose  of  the  vine.  The  same  treatment  that  is 
necessary  for  the  pear-mite  will  control  these  two  species. 

Another  species  not  commonly  seen  and  by  far  the  smallest 
mite  known,  is  the  pear-leaf  rust-mite,  which  commonly  at- 
tacks the  foliage  of  the  pear  and  which  is  recognized  by  a 
rusty  appearance  of  the  infested  leaves.  Treatment  with 
sulfur  in  any  form  is  all  that  is  necessary  to  control  this 
species. 

355.  Opportunities  for  insect  study. — Students  frequently 
have  the  idea  that  study  must  be  confined  to  books.  Nothing 
could  be  further  from  the  truth.  Books  help,  most  certainly, 
but  they  never  can  take  the  place  of  observation  at  first  hand. 
In  insects  the  student  has  a  most  fertile  field  for  observation 
and  study.  He  will  find  everywhere  an  abundance  of  ma- 
terial. He  will  be  able  to  determine  for  himself  such  matters 
as  feeding  habits,  life  histories,  and  economic  control.  He 
should  get  assistance  from  books  on  insects,  from  his  in- 
structor and  from  experts  in  entomology.  But  it  will  not  be 
very  long,  if  he  observes  closely,  before  he  will  begin  to  dis- 
cover facts  that  no  one  else  has  noted.  He  will,  in  his  own 
small  field,  be  ahead  of  the  text-books.  He  will  be  among  those 
who  are  adding  to  the  sum  total  of  human  knowledge.  The 


244  HORTICULTURE   FOR  SCHOOLS 

facts  set  down  in  this  chapter  are  brief  summaries,  dealing 
with  a  few  insect  groups,  but  there  are  thousands  on  thou- 
sands of  different  species,  many  of  which  are  an  economic 
menace  to  the  horticulturist  and  all  of  which  furnish  fruitful 
material  for  study. 

EXERCISES 

EXERCISE  I. — Study  of  the  codlin-moth. 

Materials. — "Wormy"  apples  or  pears;  knife;  a  few  collecting 
bottles  or  small  vials  partially  filled  with  3  to  5  per  cent  solution  of 
formalin. 

Procedure. — Remove  the  codlin-moth  larva  from  the  apples  or  pears 
by  cutting  them  first  into  halves.  Make  careful  drawings  of  the 
burrows  of  the  larva  in  the  fruit.  Draw  a  larva.  Describe  the  appear- 
ance, including  the  size,  color,  and  shape.  Notice  the  entrance  hole 
through  the  side  or  end  of  the  fruit,  and  the  mass  of  frass  around 
the  core.  Read  as  many  references  on  the  codlin-moth  as  possible. 
Include  in  your  notes  facts  relating  to  its  distribution,  a  list  of 
the  kinds  of  fruits  attacked  by  it,  and  an  account  of  the  best  methods 
of  control. 

EXERCISE  II. — Study  of  apple-tree  borer. 

Materials. — Sharp  knife;  trees  infested  with  borers;  vials  filled  with 
3  to  5  per  cent  solution  of  formalin. 

Procedure. — (1)  Examine  trees  infested  with  the  borers.  Notice  the 
excrement  or  castings  at  the  base  of  the  trees  infested  with  borers  and 
the  discoloration  of  the  bark  above  the  burrows.  (2)  With  the  knife 
cut  out  some  of  the  borers  and  preserve  them  in  the  vials  containing 
formalin.  Make  drawings  of  the  borer  and  describe  it  briefly.  Read 
as  many  references  as  possible  on  the  borer.  Include  in  your  notes 
the  life  history,  habits,  and  control  measures  for  the  borer. 

EXERCISE  III. — Study  of  red-humped  caterpillar,  tomato-worm,  or 
other  larvae. 

Materials. — Small  bottles  containing  3  to  5  per  cent  formalin  solution; 
infested  plants  or  trees. 

Procedure. — Study  the  type  and  extent  of  the  injury  done  by  the 
larva.  Note  its  mouth-parts.  Preserve  some  of  the  larvae.  Write  a 
complete  account  of  the  nature  of  the  work  of  the  insect,  its  life  history, 
distribution,  food  plants,  and  control  measures. 


INSECTS  AND   THEIR  CONTROL  245 

EXERCISE  IV. — Study  other  insects  common  in  your  locality,  follow- 
ing the  above  methods. 

Make  studies  of  the  egg,  larva,  pupa,  and  adult  stages  wherever 
possible. 

EXERCISE  V. — Study  of  insecticides. 

Materials. — As  many  insecticides  as  possible;  glass  jars  or  glass 
cylinders;  water. 

Procedure. — Study  each  material  as  to  the  following:  Form,  whether 
solid  or  liquid;  color,  fineness,  solubility  in  water,  precipitation. 

EXERCISE  VI. — Test  for  inert  material  in  paris  green. 

Materials. — Samples  of  paris  green,  strong  ammonia,  test-tubes. 

Procedure. — Dissolve  a  small  amount  of  paris  green  in  a  test-tube 
half  filled  with  strong  ammonia.  The  paris  green  dissolves  but  inert 
material  remains  in  the  form  of  a  precipitate. 


CHAPTER  XVII 
PLANT  DISEASES 

PLANT  pathology  is  a  comparatively  new  science.  It  is 
only  within  recent  years  that  it  has  been  recognized  that 
plants  are  subject  to  diseases  just  as  are  animals,  and  that 
these  diseases  in  turn  are  proper  topics  for  scientific  study. 
It  has  been  vaguely  recognized  for  a  long  time  that  certain 
factors  have  retarded  the  activity  of  the  plant,  causing  loss 
of  crops  and  in  many  cases  entire  destruction  to  the  plants 
involved.  A  scientific  study  of  the  phenomena  was  not  under- 
taken, however,  until  well  along  toward  the  close  of  the 
nineteenth  century.  At  present,  every  well  organized  college 
of  agriculture  has  a  department  of  plant  pathology;  and 
research  in  this  field  is  adding  immensely  to  man's  knowledge 
of  the  subject  and  consequently  to  his  power  of  control. 

356.  Causes  of  plant  diseases. — The  cause  of  most  plant 
diseases  is  some  invading  organism  belonging  to  the  lower 
forms  of  life,  that  is,  to  the  bacteria  and  other  fungi.    It  may 
be  said  in  passing,  that  a  fungus  is  itself  a  plant  that  possesses 
no  green  coloring  matter.    On  that  account,  it  cannot  manu- 
facture its  own  food  and  it  lacks  in  structure  many  of  the 
characteristics  of  the  higher  plants.     Organisms  of  this  sort 
invade  the  tissue  of  the  higher  forms,  sapping  the  nourish- 
ment from  them,  and  deranging  their  functions  in  such  ways 
as  to  produce  symptoms  of  disease. 

357.  Fungi. — As  already  stated,  fungi  are  plants;   they 
are  not  like  those  with  which  we  are  acquainted,  in  that  they 
are  very  much  simpler  in  their  structure.    They  have  no  roots, 
stem,  leaves,  flowers,  or  seeds,  as  these  terms  are  defined  in 

246 


PLANT  DISEASES  247 

the  higher  plants.  They  consist  of  thread-like  filaments 
which  may  occur  singly  or  in  tangled  masses,  or  organized 
into  more  or  less  definite  forms.  The  fungi  have  many  dif- 
ferent degrees  of  complexity,  from  the  exceedingly  simple 
bacteria,  consisting  of  only  one  cell  with  its  contents,  to  the 
very  complicated  mushroom  with  its  thousands  of  cells  and 
intricate  structure.  But  even  the  complexity  of  structure 
in  the  mushroom  does  not  compare  with  the  differentiation 
of  tissues  in  the  simplest  of  the  flowering  plants.  These 
fungi  have  no  flowers  and  produce  no  seeds  in  the  botanical 
sense.  Instead,  they  have  reproductive  bodies  called  spores, 
which  are  usually  exceedingly  small,  and  are  easily  dis- 
tributed from  place  to  place.  Some  idea  of  their  prevalence 
may  be  gained  from  the  fact  that  ordinary  bread  placed  under 
conditions  of  warmth  and  moisture  will  invariably  develop 
bread  mold;  and  this  mold  is  merely  one  among  thousands 
of  similar  fungi. 

358.  How  fungi  grow. — Every  green  leaf  contains  thou- 
sands of  very  minute  green  particles  called  chlorophyll  bodies. 
These  are  the  active  workers  which  enable  these  plants  to 
change  the  crude  sap  received  from  the  ground  into  manu- 
factured food  such  as  starch,  sugars,  fats,  and  oils.1  Fungi, 
however,  possess  no  chlorophyll;  and  since  they,  like  all 
other  plants,  must  have  these  manufactured  foods,  it  follows 
that  they  can  live  only  on  the  food  manufactured  by  the 
higher  organisms.  All  fungi  are,  therefore,  either  parasites 
or  saprophytes;  that  is,  they  live  either  on  living  plants  or 
animals,  or  on  dead  material.  It  is  the  former  class  that  is 
especially  active  in  producing  plant  diseases. 

The  spores  (Fig.  126)  of  the  fungus  are  carried  in  one  way 
or  another  to  the  surface  of  the  leaf  or  stem.  If  conditions  are 
correct  (in  general,  if  the  air  is  warm  and  humid),  these 
spores  germinate  and  penetrate  the  surface  tissue  of  the  plant. 
The  new  fungi  then  grow  down  through  the  cells  of  the  host 

»  See  Chapter  II. 


248 


HORTICULTURE  FOR  SCHOOLS 


SPORES 


extracting  nourishment  and  rendering  them  useless.  As  this 
process  goes  on,  the  fungus  gradually  gains  in  size  and 
strength,  and  spreads  rapidly  in  all  directions  to  the  un- 
affected portions  of  the  plant  tissue.  After  a  certain  stage  is 
reached,  the  fungus  puts  forth  a  new  type  of  growth  which, 
in  most  cases,  extends  outward  through  the  epidermal  cells 
of  the  plant  into  the  air.  On  the  ends  of  this  new  growth, 
sacs  form  containing  spores.  These  are  soon  scattered  to 
other  leaves  or  plants  and  the  process  begins 
all  over  again.  Since  in  many  cases  the  spore- 
sacs  produce  hundreds  and  even  thousands  of 
spores,  and  since  each  fungus  bears  many  such 
sacs,  it  is  easy  to  understand  that  the  disease 
will  spread  very  rapidly  unless  checked. 

359.  Control. — It  is  clear  that  the  fungus 
must  be  controlled  before  it  gains  access  to  the 
tissues  of  the  plant.  This  is  accomplished  in  a 
number  of  different  ways.  If  the  spores  are  car- 
ried to  the  fields  by  the  seed,  the  natural  method 
is  that  of  seed  disinfection.  The  material  com- 
monly used  for  the  purpose  is  a  solution  of 

FIG.  126.— A  fun-    -  ».  -  .  ,  ,.  ~ 

gus  showing  formalin  or  of  corrosive  sublimate.    Spores  gain 


access  commonly  through  wounds  in  the  plant. 
It  is  obvious  that  every  care  must  be  taken  to  avoid  injury 
and  thus  reduce  the  possibility  of  infection  to  a  minimum. 
Very  frequently  decay  is  caused  in  fruit  by  careless  handling, 
which  bruises  the  skin  and  provides  means  of  access  for  the 
spores.  In  view  of  these  facts,  the  method  of  fruit  handling 
becomes  of  the  utmost  commercial  importance. 

The  fungicide  most  commonly  employed  is  some  form  of 
sulfur.  This  may  be  put  on  the  plant  either  in  the  dry 
state  or  it  may  be  applied  in  the  form  of  a  spray,  the  most 
common  materials  used  being  lime  sulfur  and  bordeaux 
mixture. 

360.    Bacteria  are   very  minute   organisms  exceedingly 


PLANT  DISEASES  249 

simple  in  structure,  consisting  of  a  single  cell  only.  They  are 
almost  universally  present.  If  one  should  wipe  one's  finger 
across  the  desk  there  will  be  literally  thousands  of  bacteria 
on  the  finger  tip.  A  glass  of  ordinary  milk,  even  if  the  purest 
certified,  will  probably  contain  more  than  a  hundred  thousand 
bacteria.  If  the  milk  has  not  been  handled  with  great  care, 
this  number  may  be  counted  in  the  hundreds  of  millions. 
The  earth  swarms  with  bacteria,  many  of  which  are  benefi- 
cial to  plant  life.  But,  on  the  other  hand,  many  are  injurious 
and  the  total  injury  by  them  yearly  is  enormous. 

Reproduction  takes  place  with  such  rapidity  that  a  single 
bacterium  may  in  the  course  of  a  day  or  two  increase  under 
favorable  conditions  to  many  millions  of  individuals.  If 
climatic  or  other  factors  are  unfavorable,  they  have  the  power 
to  form  hard  crusts  about  themselves  and  in  this  state  may 
remain  quiescent  for  months  or  even  years,  ready  to  grow  and 
multiply  whenever  the  environment  is  favorable. 

Bacteria  multiply  by  a  process  of  simple  division.  One 
bacterium  divides  into  two,  these  into  four,  then  eight,  six- 
teen and  so  on.  If  such  division  takes  place  every  hour  (as 
is  sometimes  the  case,  when  food  and  temperature  factors 
are  favorable)  it  is  a  matter  of  simple  arithmetical  com- 
putation to  ascertain  the  number  to  which  one  bacterium 
would  increase  in,  say,  twenty-four  hours.1 

Some  bacteria  are  motile,  that  is,  they  have  propelling 
organs  by  means  of  which  they  are  able  to  move  through  a 
limited  space.  Others  have  no  such  structures.  All  bacteria 
thrive  best  under  conditions  of  warmth  and  moisture, 
coupled  with  abundance  of  food  material. 

361.  Pear-blight  (Fig.  127)  is  one  of  the  diseases  known  to 
be  directly  due  to  bacteria.  They  gain  access  usually  either 
through  the  flowers  or  through  the  tender  growing  parts  of 
the  plant,  and  then  spread,  attacking  the  cambium  layer 
just  beneath  the  bark.  This  cambium  is  the  actively  growing 

1  It  is  suggested  that  the  student  make  the  computation. 


250 


HORTICULTURE  FOR  SCHOOLS 


portion  of  the  plant,  and  here  the  bacteria  that  produce  the 
disease  grow  and  multiply  with  amazing  rapidity.  From  the 
tips  of  the  branches  they  spread  downward,  killing  the  limb 

as  they  advance.  The  leaves  are 
left  without  nourishment  and  very 
soon  wilt  and  die,  making  the  limb 
appear  as  if  it  had  been  injured  by 
too  much  heat.  On  this  account, 
the  disease  is  sometimes  called  fire- 
blight.  If  the  bacteria  gain  access 
through  a  small  branch  which  grows 
on  one  of  the  larger  limbs,  the 
disease  may  entirely  encircle  and 
kill  it;  or  if  they  gain  access 
through  suckers  that  grow  at  the 
base  of  the  tree,  they  may  kill  the 
FIG.  127.— Pear-blight  A  diseased  entire  tree  in  a  similar  way  in  a 

twig;   B,  healthy  twig.  yery  short  i[mQ 

It  has  been  demonstrated  that  insects  flying  from  flower 
to  flower  are  chiefly  instrumental  in  spreading  the  disease. 
Bees  are  probably  the  chief  agencies  in  this  respect.  These 
come  in  contact  with  the  disease  on  one  plant  or  part  and 
then  carry  the  bacteria  with  them  when  they  fly  to  other 
unaffected  portions. 

A  limb  or  other  part  of  the  tree  that  has  been  attacked 
cannot  be  cured.  The  bacteria  are  located  under  the  bark 
where  they  cannot  be  reached  by  any  spray  and  are  not  sub- 
ject to  surface  control.  It  has  been  necessary,  therefore,  to 
devise  other  means  of  treatment,  such  as  amputation  of  the 
diseased  parts.  Wherever  wilting  appears,  indicating  the 
presence  of  disease,  the  limb  should  be  cut  off  immediately. 
To  avoid  any  possible  infection,  the  scissors  or  pruning- 
shears  with  which  the  cut  has  been  made  should  then  be 
dipped  in  corrosive  sublimate1  solution  prepared  one  to  one 
thousand.  The  wound  should  be  disinfected  with  a  solution 


Plate  VII. — Upper:  A  thrifty  vineyard  with  orchard  in  background. 
Lower:  Strawberries  grown  in  matted  rows  in  young  apple  orchard. 


PLANT  DISEASES  251 

of  cyanide  of  mercury1  at  a  strength  of  one  gram  to  five 
hundred  cubic  centimeters  of  water.  Corrosive  sublimate  is 
not  the  best  disinfectant  for  wounds,  and  the  other  does  not 
work  well  as  a  disinfectant  for  tools. 

The  limb  which  has  been  cut  off  must  be  burned  at  once. 
In  this  way  the  disease  can  be  definitely  kept  in  check,  but 
in  those  regions  where  it  is  well  established,  eternal  vigilance 
is  the  price  which  each  pear-grower  must  pay  if  he  hopes  to 
keep  his  orchard.  Sometimes  the  disease  can  be  detected  in 
whiter  through  the  shriveling  of  the  bark,  but  this  calls  for 
expert  observation  and  for  the  amateur  the  surest  way  is  to 
wait  until  the  leaves  appear  in  spring,  when  the  progress  of 
the  disease  can  be  definitely  noted. 

Considerable  thought  is  being  given  to  resistant  stocks. 
Some  varieties  of  Chinese  pears  are  not  susceptible  to  blight 
and  these  are  being  used.  Such  a  method  does  not  save  the 
tops  from  being  attacked,  but  it  does  insure  that  the  root 
will  not  be  killed  by  the  disease. 

362.  Powdery  mildew,  found  chiefly  on  the  grape,  has 
been  known  for  three-fourths  of  a  century  and  is  a  constant 
problem  to  grape-growers  not  only  in  the  United  States  but 
throughout  Europe. 

It  can  be  seen  readily  on  the  leaves  of  diseased  vines, 
occurring  on  both  the  upper  and  lower  surface  as  whitish 
blotches,  more  or  less  rounded  in  shape.  It  does  not  confine 
itself  to  the  leaf,  however,  but  attacks  all  parts  except  the 
root.  Blossoms  which  are  mildewed  do  not  set  their  fruit,  and 
fruit  itself,  if  it  be  affected,  soon  ceases  growth  and  falls,  or 
develops  irregularly  and  fails  to  ripen.2 

Thousands  of  tons  of  sulfur  are  used  every  year  in  the 
grape-growing  sections  of  the  United  States  in  the  control  of 
this  disease.  This  sulfur  is  carried  on  the  back  of  the 

1  Both  substances  are  very  poisonous!     Young  children  should  never 
handle  either. 

2  Stevens  and  Hall :  Diseases  of  Economic  Plants. 


252  HORTICULTURE  FOR  SCHOOLS 

operator  in  a  sort  of  knapsack,  which  connects  with  a  bellows. 
The  operator  works  the  bellows  as  he  walks  along  the  row, 
giving  each  vine  a  thorough  dusting.  A  power-sprayer  for 
the  purpose  is  now  coming  into  use.  Two  applications,  some- 
times three,  are  necessary  to  control  the  disease.  The  fungi 
grow  most  readily  when  warmth  and  moisture  are  present. 
Clear  cool  weather  acts  as  a  check  and  reduces  the  number 
of  applications  of  sulfur  necessary. 

Mildew  affects  many  other  plants  beside  the  grape.  It  is 
found  frequently  on  rose  bushes,  and  appears  also  to  some 
extent  on  peaches,  apples,  currants,  garden  beans,  and  others. 
In  addition  to  the  measures  named  above,  plants  should 
usually  be  placed  in  positions  where  they  re- 
ceive fairly  constant  sunlight,  for  this  assists 
materially  in  keeping  down  the  disease. 

363.    Crown-gall  (Fig.  128)  is  a  very  com- 
mon disease  of  deciduous  trees.    As  the  name 
indicates,  it  affects  the  crown  of  the  root,  just 
below  the  surface  of  the  ground.      It  is  a  bac- 
terial disease.   When  the  bacteria  gain  access  to 
the  root  of  the  plant,  they  cause  enlargement 
of  the  diseased  tissue,  producing  a  gall-like  ap- 
pearance.    This  gall  may  first  be  located  on  one 
side  of  the  root  only,  but  as  the  disease  pro- 
gresses it  gradually  spreads  around  the  root, 
until  the  entire  crown  is  affected.     As  soon 
Fl^11128-~Crown"  as  this  occurs,  a  circle  of  the  cambium  layer 
is  killed,  connection  with  the  root  is  severed, 
and  the  tree  dies.    From  the  time  the  disease  first  appears, 
several  years  usually  pass  before  it  kills  the  tree. 

No  cure  is  known.  When  the  infestation  is  light,  it  is  some- 
times recommended  to  cut  away  the  diseased  portion,  and 
paint  with  some  antiseptic  to  stop  the  spread  of  the  disease. 
In  general,  however,  this  is  not  practicable.  It  is  always 
necessary,  when  buying  young  fruit-trees,  to  watch  the  roots 


PLANT  DISEASES 


253 


very  carefully  indeed,  since  this  disease  usually  makes  its 
appearance  in  the  first  place  in  the  nursery.  If  nursery  stock 
is  secured  that  is  absolutely  free  from  crown-gall,  the  chances 
of  development  later  in  the  orchard  are  very  much  lessened. 
Every  precaution  must  be  taken  to  see  that  roots  are  not  in- 
jured in  the  process  of  cultivation  or  in  other  ways.  As  before 
pointed  out,  the  disease  is  transmissable  and  it  finds  ready 
access  through  wounds,  especially  if  these  are  close  to  the 
surface  of  the  ground .  There 
is  a  possibility  that  a  root 
may  be  found  which  will  be 
immune  to  this  disease. 

364.  Potato  scab 
(Fig.  129).— This  common 
disease  of  the  potato,  occur- 
ring in  all  parts  of  the 
country,  causes  an  immense 
amount  of  damage.  It  is 
readily  recognized,  for  it 
covers  the  tuber  with  rough  brown  blotches  as  shown  in 
Fig.  129.  The  outer  tissue  is  destroyed  and  the  tuber  be- 
comes unsightly  in  appearance. 

The  disease  is  produced  by  a  fungus  which  gains  access 
from  the  seed  or  from  the  soil.  Since  it  lives  in  the  ground 
from  year  to  year,  fields  in  which  it  has  appeared  should  not 
be  planted  to  potatoes  or  root-crops  for  four  or  five  seasons 
after  it  was  last  detected.  There  is  no  other  way  known  at 
present  whereby  it  can  be  eradicated  from  the  soil  after  it  has 
once  gained  access. 

The  common  treatment  to  prevent  infection  from  seed 
potatoes  is  by  soaking  in  formaldehyde  solution.  Of  course, 
potatoes  which  are  in  the  least  scabby  or  which  are  known  to 
have  come  from  a  field  where  scab  has  been  present,  should 
not  be  used  for  seed.  It  is  not  possible,  however,  in  the 
larger  number  of  cases,  to  ascertain  the  facts  with  regard  to 


FIG.  129.— Potato  scab. 


254  HORTICULTURE  FOR  SCHOOLS 

seed  potatoes,  and  the  precaution  should  be  taken  of  treating 
all  seed. 

The  method  is  as  follows :  Dissolve  a  fluid  ounce  of  forma- 
lin in  two  gallons  of  water,  and  soak  potatoes  in  the  solution 
for  at  least  an  hour.  The  seed  may  then  be  used  at  once, 
or  dried  off  and  used  as  desired.  If  a  large  amount  of  seed 
is  to  be  treated,  the  solution  should  be  prepared  by  the  barrel, 
but  the  proportions  given  above  are  maintained. 

365.  Brown-rot  is  a  very  common  disease  in  all  parts  of 
the  United  States.  It  attacks  the  peach  especially  and  other 
stone-fruits  as  well.  Its  development  is  favored  by  warmth 
and  especially  by  a  moist  condition  of  the  atmosphere.  The 
losses  which  can  be  traced  to  it  are  always  considerable  and 
sometimes  very  heavy. 

The  disease  is  produced  by  a  species  of  fungus  which  gains 
access  to  the  fruit  and  grows  there,  destroying  the  tissue. 
After  the  fungus  has  progressed  sufficiently,  the  fruit  turns 
dark  in  color  and  begins  to  shrivel.  This  is  the  first  indication 
of  the  progress  of  the  disease.  From  the  fruit,  the  fungus 
may  enter  the  limbs,  but,  as  a  rule,  the  woody  parts  of  the 
plant  are  not  very  susceptible. 

Frequently  fruit  which  has  become  infected  with  the  dis- 
ease is  allowed  to  hang  on  the  trees  and  forms  a  prolific  source 
of  trouble  during  the  following  year.  Spores  are  present  in 
great  numbers  in  these  dried-up  fruits  and  are  easily  carried 
to  the  new  ones.  Access  is  facilitated  if  the  fruit  is  bruised, 
but  the  disease  also  gains  entrance  even  where  the  skin  is 
whole  and  healthy.  The  first  precaution  in  the  treatment  of 
the  disease  is,  therefore,  to  see  that  all  of  the  affected  fruit 
of  the  previous  year  is  taken  off  the  trees  and  either  carried 
off  and  burned  or  plowed  under  deeply  enough  so  that  the 
spores  do  not  come  to  the  surface  of  the  ground. 

The  next  step  in  control  is  the  use  of  bordeaux  mixture 
during  the  late  dormant  season  of  a  strength  of  approximately 
6-6-50.  It  is  impossible,  however,  to  reach  all  of  the  spores 


PLANT  DISEASES  255 

with  the  bordeaux  and,  while  commercial  results  can  be 
secured,  entire  eradication  is  practically  out  of  the  question. 

There  is  a  disease  of  lemons  which  is  also  called  brown-rot, 
but  this  is  caused  by  a  different  fungus.  As  the  name  indi- 
cates, the  lemon  turns  brown  after  the  disease  has  penetrated 
the  interior  of  the  fruit.  It  is  necessary  in  treatment 
to  spray  the  ground  thoroughly  with  bordeaux  mixture, 
especially  in  the  vicinity  of  the  trees,  for  rain  splashing 
the  ground  may  carry  the  spores  to  the  fruit  on  the 
lower  part  of  the  tree.  The  prevalence  of  this  fungus  is 
one  of  the  factors  which  make  careful  handling  so  neces- 
sary, for  wherever  a  slight  bruise  occurs,  the  spores  are 
able  to  gain  access  to  the  interior  of  the  fruit  and  decay 
quickly  follows. 

The  same  fungus  which  causes  the  brown-rot  of  the  fruit 
is  also  responsible  for  a  gum  disease  of  the  bark,  which  has 
proved  serious.  This  is  now  kept  under  control  by  budding 
the  lemon  on  such  resistant  forms  as  Florida  sour  stock  and 
by  keeping  the  bud  union  well  above  the  ground.  When  the 
disease  appears,  it  may  be  checked 
by  scraping  off  the  injured  bark 
and  then  painting  the  affected 
parts  with  a  mixture  of  blue-stone 
and  lime.  One  pound  of  blue- 
stone  and  two  pounds  of  lime  are 
dissolved  separately  in  three  quarts 
of  water  and  the  two  solutions  are 
then  mixed. 

366.   Shot-hole  fungus  (Fig.  130) 

,.  .          ,  •   ,  „         FIG.  130.— Shot-hole  fungus. 

produces  a  disease  in  which  small 

round  discolorations  or  holes  appear  on  the  leaves  and 
fruit.  The  manner  in  which  these  are  scattered  suggests 
the  effect  of  a  charge  of  shot  from  a  shot-gun.  A  num- 
ber of  different  species  are  responsible  for  the  disease. 
Like  all  other  fungi,  these  must  be  treated  before  they  gain 


256  HORTICULTURE  FOR  SCHOOLS 

access  to  the  plant  if  injury  is  to  be  prevented.  The  sprays 
most  commonly  used  are  bordeaux  and  lime-sulfur,  applied 
in  the  early  spring. 

367.  Anthracnose  occurs  on  a  large  number  of  plants. 
On  the  bean  it  produces  dark  markings  and  blotches  on  the 
pods,  stems,  and  leaves.     These  blotches  gradually  spread 
until  they  produce  large  irregularly  shaped  markings.    The 
raspberry  and  other  berries  are  frequently  affected,  the  dis- 
ease appearing  as  purplish  spots  which  gradually  become 
larger  and  sunken  in  the  center.    A  form  similar  to  that  on 
the  raspberry  has  done  an  immense  amount  of  damage  to  the 
grape.    Legumes  other  than  the  bean  are  also  affected  by  the 
disease  and  a  large  number  of  other  plants  are  not  immune. 

Spraying  does  not  suffice  in  the  control  of  the  disease.  The, 
affected  parts  should  be  removed  and  burned,  and  care  should 
be  taken  that  only  healthy  plants  are  set  out.  Since  the 
spores  are  apparently  carried  by  seed,  especially  of  beans,  that 
source  of  infection  must  not  be  overlooked.  When  the  dis- 
ease appears,  a  rotation  of  crops  is  desirable  that  will  use  for 
four  or  five  years  such  vegetables  and  other  plants  as  are 
immune  to  the  attacks  of  the  organism. 

368.  Root-rot. — A  number  of  diseases  are  grouped  under 
the  general  name  of  root-rot.    These  are  produced  by  several 
different  fungi,  called  as  a  class  Rhizoctonia.  As  these  diseases 
progress,  the  smaller  roots,  or  indeed  the  whole  root  system, 
may  be  killed,  although  the  observer  has  no  knowledge  of 
what  is  happening  until  the  top  withers  or  even  dies.    These 
diseases  are  especially  prevalent  on  heavy  soils,  or  when  the 
drainage  and  aeration  are  not  good.    A  thorough  cultivation 
of  the  soil,  together  with  proper  drainage,  is  the  easiest  and 
cheapest  way  to  protect  the  roots.   Various  plants  have  been 
reported  as  subject  to  these  diseases,  among  which  are  alfalfa, 
the  orange,  cotton,  and  the  grape.    Among  the  vegetables, 
the  bean,  pea,  potato,  tomato,  beet,  radish,   and   certain 
others  are  susceptible. 


PLANT  DISEASES 


257 


Bitter-rot  (Fig.  131)  is  an  example  of  a  disease  which 
occurs  on  the  fruit  in  one  form,  and  on  the  wood  in 
another.  This  fungus, 
when  it  gains  access 
to  the  wood,  causes 
a  disease  known  as 
bitter-rot  canker. 

369.  Damping-off 
gives  considerable 
trouble  especially  in 
the  hotbed.  The 
young  seedlings  with- 
er and  fall  over  and  FlG-  isi.-Appie  bitter-rot. 

an  examination  reveals  that  the  stem  has  collapsed  near  the 
point  where  it  emerges  from  the  ground.  The  disease  spreads 

rapidly,  and  frequently 
a  large  number  of  plants 
are  affected  before  it  is 
discovered.  The  condi- 
tions which  especially 
favor  its  development 
are  moisture  and 
warmth. 

As  the  seedlings  crowd 
up  out  of  the  ground  and 
as  the  leaves  develop 
above,  there  is  a  space 
between  the  ground  and 
the  leaves  where  mois- 
ture does  not  have  a 
chance  to  evaporate 
and  this  makes  an  ideal 
condition  for  the 


FIG.  132. — Peach-yellows. 


development  of  fungus.  When  the  hotbed  is  kept  too  warm, 
a  large  number  of  plants  may  be  lost  in  this  way.    Care  must 


258 


HORTICULTURE  FOR  SCHOOLS 


be  exercised  also  to  prevent  moisture  from  standing  on  the 
seedlings  any  longer  than  necessary.  It  is  generally  desirable 
to  water  greenhouses  and  hotbeds  in  the  morning  rather  than 
at  night,  for  the  sunlight  will  dry  off  the  plants  and  drive  the 
moisture  from  the  stem.  If  moisture  is  allowed  to  remain  on 
the  plants  over  night,  they  are  much  more  susceptible  to  the 
damping-off  disease. 

370.  Control  of  diseases. — The  control  of  plant  diseases 
is  intimately  connected  with  the  whole  subject  of  care  in  all 
its  aspects.  The  cultivation  of  the  ground,  the  application 
of  irrigation  water,  the  methods  of  pruning,  and  the  disposal 
of  prunings  and  other  rubbish,  all  have  a  direct  influence  on 

disease  control.  The 
orchardist  or  gardener 
must  not  only  know  a 
great  deal  about  bacteria 
and  fungi  and  the  sprays 
with  which  tr\ey  may  be 
combated,  but  also  must 
pay  attention  to  every 
detail  which  enters  into 
the  business  of  good 
management.  Only  by  so 
doing  can  he  hope  to 
wage  a  successful  warfare 
against  plant  diseases. 

The  first  step  in  control 
of  disease  is  the  ascertain- 
ing of  the  cause.  This  is 
well  illustrated  in  the  case 
of  peach-rosette  and  peach-yellows  (Figs.  132  and  133),  two 
diseases  the  causes  of  which  are  still  unknown.  Their 
control  is  very  difficult  on  that  account. 


FIG.   133. — Peach-rosette. 


PLANT  DISEASES  259 


EXERCISES 

EXERCISE  I. — Crown-gall. 

Material. — Potted  geranium  plant  with  actively  growing  stems. 
Secure  specimens  in  the  locality  of  crown-gall  injury.  (This  will  be 
found  on  almost  all  of  the  deciduous  fruit-trees,  especially  the  peach.) 

Procedure. — Note  with  regard  to  crown-gall  the  following  points: 
The  general  appearance  of  the  diseased  portion,  its  location  with  regard 
to  the  surface  of  the  ground,  its  effect  on  the  living  tissue  of  the  plant, 
the  apparent  depth  of  penetration  into  the  interior  of  the  plant,  the 
appearance  of  the  center  of  the  diseased  portion  as  compared  with  its 
outer  edges  and  general  appearance  of  the  plant  on  which  the  crown-gall 
is  found. 

Transmit  the  disease  from  the  affected  plant  to  a  healthy  young 
shoot  of  geranium  in  the  following  manner:  Insert  the  point  of  a  knife 
blade  into  tissue  affected  with  crown-gall  and  then  insert  the  blade 
into  the  young  stem  of  the  geranium. 

Each  student  should  make  this  inoculation,  some  using  the  center  of 
the  crown-gall  tissue  and  others  the  outer  edge.  The  geranium  stems 
thus  inoculated  should  be  watched  carefully  from  day  to  day.  The 
effect  of  the  inoculation  will  probably  begin  to  appear  within  a  month. 

EXERCISE  II. — Diseases  affecting  projects. 

Materials. — Diseased  portions  of  plants  from  students'  projects. 

Procedure. — Make  a  study  of  the  diseased  plants  either  in  the 
laboratory  or  in  the  field.  Identify  the  disease  by  referring  either  to 
Chapter  XVII,  to  books  of  reference  on  plant  diseases,  to  bulletins 
published  by  the  experiment  stations,  or  in  the  event  that  the 
identification  is  still  uncertain,  by  direct  correspondence  with  your 
state  experiment  station. 

Write  up  a  full  account  of  the  disease  including  the  cause,  nature  of 
injury,  control,  and  all  other  material  of  interest. 

EXERCISE  III. — Study  some  of  the  common  fungicides  in  the  same 
way  as  suggested  for  the  study  of  insecticides  in  the  exercises  following 
the  chapter  on  "Insects." 

EXERCISE  IV. — Making  various  spray  mixtures. 

Materials. — Various  materials  for  making  spray  mixtures,  utensils 
for  making,  and  the  like. 

Procedure. — Make  spray  materials  such  as  bordeaux  solution  and 
lime  sulfur. 


CHAPTER  XVIII 

MARKET  PREPARATION,  TRANSPORTATION, 
AND  STORAGE 

IN  the  moving  of  fruits  and  vegetables  from  the  place  where 
they  are  grown  to  the  market,  and  thence  to  the  consumer, 
three  stages  are  involved : 

(1)  The  market  preparation  stage  includes  such  opera- 
tions as  picking  or  otherwise  harvesting  the  crop,  hauling, 
cleaning,  grading,  sizing,  drying  and  curing,  packing,  and 
loading  on  the  cars;  in  short  all  the  operations  necessary  to 
gather  the  commodity  and  place  it  in  proper  condition  for 
shipment  and  sale. 

(2)  The   transportation   stage  includes  the  loading  ana 
routing  of  cars,  and  such  other  operations  as  are  necessary  to 
the  safe  arrival  of  the  product  at  the  market.    If  the  shipment 
takes  place  in  refrigerator-cars,  as  is  the  common  practice 
with  car-lots,  the  cars  are  iced  and  sealed.    The  commodity 
is  then  hurried  to  its  destination  by  fast  freight.    Sometimes 
fruit  is  kept  in  cold  storage  for  a  time  before  it  is  sent  to  the 
market. 

(3)  Marketing  and  selling  stage. — In  this  stage  are  in- 
cluded all  operations  pertaining  to  the  actual  sale  or  disposal 
of  the  crop.     Among  them  are  distribution,  handling  in 
markets,  advertising,  and  systems  of  selling. 

Producers  are  becoming  increasingly  appreciative  of  the 
fact  that  the  operations  of  these  different  stages  are  best  per- 
formed by  specialists  who  are  able  to  give  their  entire  time 
each  to  a  particular  phase.  It  happens  that  in  the  past  most 
attention  has  been  paid  to  the  processes  of  production.  It  is 

260 


MARKET  PREPARATION,  TRANSPORTATION,  STORAGE  261 

natural  that  this  should  have  been  so,  for  it  is  with  produc- 
tion that  the  grower  is  most  intimately  concerned  and  the 
problems  come  home  to  him  by  personal  contact.  Only  in 
comparatively  recent  years  has  attention  been  directed  to- 
ward a  study  of  the  fundamentals  involved  in  marketing, 
problems  just  as  vital  to  the  success  of  the  fruit  and  vegetable 
industry  as  are  those  of  production. 

It  was  not  many  years  ago  that  fruit  and  vegetables  were 
grown  only  as  secondary  crops  and  marketed  in  towns  and 
cities  adjacent  to  the  farms.  Now  they  are  raised  on  a  large 
scale  and  some  of  the  most  perishable  products  are  marketed 
even  thousands  of  miles  distant  from  the  point  where  they 
are  produced.  It  is,  therefore,  necessary,  in  this  age  of  com- 
mercial production,  that  each  step  of  the  process  from  the 
growing  of  the  product  to  its  final  sale  to  the  consumer  should 
be  thoroughly  understood  by  the  growers  themselves.  In  the 
pages  which  follow  the  problems  of  marketing  will  be  dis- 
cussed with  reference  to  fruits  alone;  but  it  must  be  kept 
in  mind  that  what  is  said  applies  to  vegetables  as  well,  though 
on  a  smaller  scale. 

371.  Growing  and  marketing. — There  is  vital  connection 
between  the  conditions  in  the  orchard  or  field  and  that  of  the 
product  when  it  is  finally  placed  on  the  market.    Poor  care 
in  the  form  of  inadequate  cultivation  or  fertilization  reacts 
on  the  quality  of  the  product.    Improper  pruning  of  trees 
results  in  fruit  of  poor  size  or  so  marred  by  scratches  that  it 
cannot  be  sold  as  a  first-class  product.     Insufficient  or  too 
much  moisture  affect  the  final  flavor  of  the  fruit  unfavorably. 
A  season  during  which  weather  conditions  are  unfavorable 
frequently  produces  a  large  proportion  of  fruit  of  poor  quality 
or  appearance. 

372.  The  ripening  process. — The  fruit  is  a  storehouse  of 
food  for  the  potential  plant  in  the  seed.   This  food  is  manufac- 
tured for  the  most  part  in  the  leaves  where  it  may  be  found 
in  the  form  of  starch.    Later,  it  is  changed  from  starch  to 


262  HORTICULTURE  FOR  SCHOOLS 

soluble  substances  which  are  transported  through  the  tissues 
to  the  fruit.  As  the  fruit  ripens,  the  starch  is  gradually 
changed  into  new  material,  mostly  sugar  and  fiber;  but  in 
addition  to  these  dozens  of  other  substances,  such  as  oils  and 
acids,  give  to  each  variety  its  peculiar  flavor.  In  most  ripe 
fruits  the  starch  which  formerly  was  present  in  the  green 
fruit  has  practically  all  disappeared,  and  other  substances 
have  been  formed  from  it.1 

Change  does  not  stop  there.  Very  soon  decay  begins,  and 
the  fruit  becomes  worthless  for  human  use.  In  fact,  the  tear- 
ing down  process  starts  before  the  building  up  is  completed, 
and  the  two  go  on  for  a  considerable  time  side  by  side.  At 
last  the  process  of  decay  predominates,  and  the  product 
becomes  useless  as  human  food. 

373.  The  time  for  harvesting. — Time  of  picking  and  sub- 
sequent treatment  will  vary,  depending  on  the  use  to  which 
the  fruit  is  to  be  put.  If  intended  for  a  nearby  market,  it 
will  ordinarily  remain  on  the  trees  longer  than  if  the  market 
is  at  a  distance.  If  intended  for  drying  or  canning,  it  will 
be  handled  differently  than  if  sold  as  fresh  fruit.  If  it  is  to 
be  placed  in  cold  storage,  again  certain  factors  of  successful 
practice  must  be  kept  in  mind.  Harvesting,  therefore,  calls 
for  a  constant  exercise  of  judgment  on  the  part  of  the  horti- 
culturist. 

It  is  customary  to  judge  the  ripeness  of  most  fruits  by  their 
color  and  general  appearance.  The  quality  of  the  fruit  put 
on  the  market  is  subject,  however,  to  increasingly  rigid 
standards.  This  has  led  to  the  adoption  of  scientific  tests  for 
ripeness  in  the  case  of  certain  fruits  of  whose  condition  it  is 
difficult  to  judge. 

With  grapes,  bunches  are  secured  from  sections  of  the  vine- 
yard and  from  different  places  on  the  vines  so  that  the  sample 
may  be  representative  of  all  the  fruit.  The  juice  is  then 

1  One  of  the  few  exceptions  to  this  rule  is  the  banana,  the  ripe  fruit  of 
which  contains  a  considerable  proportion  of  starch. 


MARKET  PREPARATION,  TRANSPORTATION,  STORAGE  263 

extracted  by  placing  the  grapes  in  a  muslin  bag  and  squeezing 
the  mass  with  the  fingers.  The  liquid  is  poured  into  a  glass 
cylinder  into  which  an  instrument  called  a  Balling  sacchari- 
meter  is  introduced.  It  is  necessary  to  have  enough  grape 
juice  to  float  the  saccharimeter.  The  instrument  records  the 
percentage  of  sugar  in  the  juice;  for  example,  if  25  per 
cent  of  the  weight  of  the  solution  is  sugar,  the  reading 
is  25.  The  amount  of  sugar  does  not  need  to  be  so  high 
for  table  as  for  raisin  grapes.  The  fruit  is  suitable  for  table 
use  when  it  contains  16  or  17  per  cent  of  sugar.  It  is  not 
suitable  for  raisins  until  this  percentage  has  risen  to  24  or 
25  or  higher. 

With  oranges  also  there  is  a  standard  test  for  ripeness. 
In  this  case  two  factors  must  be  taken  into  account.  The 
first  is  the  percentage  of  solids  (principally  sugar)  dissolved 
in  the  juice  of  the  fruit.  The  second  is  the  percentage  of  acid 
in  the  juice.  The  standard  depends  on  the  ratio  between  these 
two  percentages.  An  orange  is  considered  ripe  according  to 
this  test  when  there  are  eight  parts  of  soluble  solids  in  the 
juice  to  one  part  of  acid.  This  is  the  so-called  8  to  1  test. 
It  is  probable  that  in  the  future  tests  will  be  devised  for  many 
other  fruits.  Experiments  in  this  field  are  being  conducted  at 
the  present  time. 

374.  Decay. — Each  year  large  losses  of  fruit  occur  due  to 
decay  in  transit.  This  is  not  merely  the  natural  and  unavoid- 
able decay  caused  by  over-ripeness,  but  represents  largely  an 
unnecessary  loss  resulting  from  careless  handling.  Molds  of 
several  kinds,  the  most  common  of  which  is  blue-mold  or 
mildew,  attack  and  destroy  the  fruit.  It  has  been  demon- 
strated that,  as  long  as  the  skin  remains  unbroken,  the  mold 
cannot  gain  entrance,  but  the  slightest  injury,  such  as  a 
scratch  from  the  branch  of  a  tree,  a  bruise  in  handling, 
or  an  abrasion  from  the  finger-nails  of  the  packer  or 
picker,  is  sufficient  to  allow  the  fungus  to  gain  access  to 
the  fruit.  Once  the  tissue  has  been  invaded,  the  entire 


264  HORTICULTURE  FOR  SCHOOLS 

fruit  is  quickly  destroyed.  The  problem  of  the  grower  is 
to  see  that  in  each  stage  of  the  handling  the  skin  of  the 
fruit  is  kept  whole. 

375.  Picking. — The  precautions  will  differ  with  the  vari- 
ous fruits.    Raspberries  and  other  berries  are  injured  by  hold- 
ing too  many  in  the  hand  while  picking.     Even  a  matter 
seemingly  so  trivial  as  the  use  of  two  fingers  instead  of  three 
in  picking  raspberries  may  have  considerable  influence  on  the 
keeping  quality  of  the  fruit.    Oranges  and  lemons  are  not 
pulled  or  broken  from  the  stem,  but  are  cut  with  clippers  which 
have  curved  edges.    In  using  these,  care  must  be  exercised  to 
see  that  the  clippers  do  not  injure  the  fruit,  and  at  the  same 
time  that  the  stem  left  is  not  long  enough  to  puncture  any  other 
orange  which  may  come  in  contact  with  it.    It  is  a  common 
practice  in  the  case  of  the  softer  fruits  to  squeeze  them  gently 
when  picking  to  ascertain  their  ripeness.    This  is  injurious 
and  invariably  results  in  a  considerable  proportion  of  decayed 
fruit.    Even  if  the  product  is  to  be  utilized  immediately  in  the 
cannery  or  drying  yard,  injuries  of  this  sort  should  be  care- 
fully avoided. 

When  in  field-boxes  or  other  containers,  fruit  must  not  be 
heaped  up  so  that  one  box  will  cause  injury  to  the  fruit  in  the 
one  below.  Fruit  must  be  laid  in  the  picking-boxes  and  not 
thrown  or  handled  in  other  rough  ways.  Gravel  and  sand 
or  twigs  in  the  picking-boxes  are  sources  of  trouble  as  are 
also  splinters  or  nails.  The  old  rule  is  that  fruit  must  be 
handled  like  eggs;  but  this  is  rather  an  under-statement 
as,  in  many  cases,  it  must  be  treated  very  much  more 
carefully  than  eggs. 

376.  Hauling. — Care  is  essential  also  in  hauling.     The 
wagon  or  other  vehicle  should  be  provided  with  springs  to 
lessen  the  damage  by  bruising.    One  of  the  best  investments 
which  a  fruit-growing  district  can  make  is  for  good  roads;  for 
these  reduce  to  a  minimum  the  amount  of  injury  to  the  fruit 
between  the  orchard  and  the  packing-house. 


MARKET  PREPARATION,  TRANSPORTATION,  STORAGE  265 


PACKING-HOUSE    OPERATIONS 

The  packing-house  performs  today  efficiently  the  opera- 
tions which  twenty-five  years  ago  were  attempted  in  a 
desultory  way  on  the  farm.  The  fruit  is  sometimes  brushed  or 
polished  and  in  some  cases  washed.  These  processes  increase 
the  chances  for  injury  and  consequent  decay  and  have  to  be 
performed  with  the  greatest  care.  Grading  the  fruit  consists 
in  sorting  according  to  color,  quality,  and  size.  The  grading 
may  be  done  either  by  hand  or  by  machinery.  Its  purpose 
is  to  enable  the  packer  to  put  the  fruit  up  in  such  a  way 
that  each  container  is  filled  with  a  fairly  uniform  quality 
and  size. 

377.  Packing. — Systematic  packing  is  advantageous  to 
the  industry  in  several  ways.    It  results  in  a  more  attractive 
product;   and  this  always  reacts  to  create  a  better  market. 
It  adds  to  the  carrying  quality  of  the  fruit,  for  in  good  packing 
the  contents  are  placed  in  the  package  tightly  with  no  chance 
to  move  about.    It  facilitates  shipment  and  delivery  to  the 
wholesaler  or  retailer.    It  enables  a  grower,  an  association,  or 
a  community  to  build  up  through  a  period  of  years  a  reputa- 
tion for  a  good  product  so  that  the  name  on  the  outside 
of  the  package  carries  a  guarantee  of  the  quality  of  the 
goods  within. 

Just  as  in  the  processes  of  picking,  hauling,  and  grading, 
great  care  is  necessary  in  packing.  There  is  a  possibility  of 
injury  from  finger-nail  scratches,  from  throwing  the  fruit,  or 
from  squeezing  it  unduly  in  fitting  it  into  the  container.  It  is 
essential  in  filling  that  there  be  some  bulge  in  the  center  of  the 
box  and  that  the  tops  when  nailed  on  spring  outward  and 
hold  the  fruit  in  place.  This  method  would  seem  to  cause 
injury,  but  this  is  not  the  case  unless  this  bulge  in  the  center 
is  uneven  or  too  high. 

378.  Wrapping. — In  the  case  of  some  fruits,  there  is  an 
advantage  in  wrapping.    Fruits  so  treated  have  a  bright  and 


266  HORTICULTURE  FOR  SCHOOLS 

clear  appearance  when  removed  from  the  container.  Wrap- 
ping prevents  bruising  and  the  wrapping  material  absorbs 
some  moisture.  Moisture,  as  has  already  been  stated,  facili- 
tates the  growth  of  decay-producing  organisms.  The  wrap- 
per tends  also  to  isolate  any  individual  fruit  to  which  decay 
has  gained  entrance  and  the  injury  is,  therefore,  less  general 
than  it  otherwise  would  be. 

The  operation  of  wrapping  is  performed  quickly.  The 
packer  takes  the  paper  in  his  left  hand  and  the  fruit  in  his 
right.  He  throws  the  fruit  into  the  center  of  the  paper  and 
with  a  quick  twist  wraps  it  while  in  the  act  of  placing  it  in 
the  box.  Some  packers  place  with  the  right  hand,  others 
with  the  left.  This  placing  must  be  done  firmly  but  at  the 
same  time  not  too  roughly. 

All  fruits  are  arranged  systematically  in  packing  except 
grapes,  cherries,  and  berries.  These  are  placed  in  the  container 
without  arrangement  and  then  faced;  that  is,  the  top  layer  is 
packed  regularly  so  as  to  give  the  fruit  a  neat  and  uniform 
appearance.  When  apples  are  packed  in  barrels,  they  are 
placed  without  arrangement  or  assortment  in  the  barrel  and 
the  top  layer  is  faced.  In  some  localities  in  the  United  States, 
apples  are  packed  in  the  same  way  in  boxes.  As  a  rule,  how- 
ever, box-packs  are  arranged  in  layers. 

These  are  two  common  arrangements  in  the  box,  the 
straight  and  the  diagonal.  The  fruit  adjusts  itself  better  to 
the  package  with  the  diagonal  than  with  the  straight  pack. 
It  is,  therefore,  the  more  common  system  of  the  two.  The 
number  of  fruits  in  a  tier  will  be  determined  by  the  size. 
Oranges  are  fairly  elastic  and  can  be  adjusted  to  the  container. 
Apples  are  less  so  and  also  vary  greatly  in  shape,  so  that  the 
arrangement  of  a  given  size  may  have  to  be  modified  to  fit 
the  box.  In  general,  the  size  of  the  box  has  been  determined 
by  the  best  arrangement  of  the  fruit  within  and,  in  some  cases, 
more  than  one  size  has  been  adopted  to  facilitate  the  packing 
of  different  sizes  of  fruit. 


MARKET  PREPARATION,  TRANSPORT  AT  ION  .STORAGE  267 


TRANSPORTATION   AND    STORAGE 

Transportation  includes  shipping,  cooling,  refrigerating, 
railway  hauling,  switching,  and  unloading;  to  this  is  added 
storing  of  the  fruit  if  it  is  to  be  held  for  out-of -season  sale. 
At  the  present  time,  transportation  of  crops  to  market  almost 
always  includes  a  trip  by  railroad  or  boat.  Fruits  shipped 
from  country  districts  to  near-by  markets  do  not  require  the 
special  care  which  is  necessary  in  long-distance  transportation. 

379.  The  railroad. — The  growth  of  the  fruit  industry  in 
the  United  States  has  been  made  possible  by  the  develop- 
ment of  the  railroad.    The  first  trans-continental  road  was 
completed  in  1869.     Others  quickly  followed.     They  were 
built  in  advance  of  the  needs  of  the  day,  but  they  unquestion- 
ably played  a  large  part  in  hastening  the  development  of  the 
country.    Certainly  the  growth  of  the  fruit  industry  in  the 
West  and  Middle  West  would  have  been  absolutely  out  of  the 
question  had  it  not  been  for  transportation  facilities  thus 
afforded.    At  first  fruit  was  shipped  in  small  quantities;  now 
a  large  proportion  of  the  shipments  is  in  carload  or  trainload 
lot s .    Some  of  the  roads  run  regular  trains  which  carry  nothing 
but  fruit  and  which  have  the  right  of  way  over  all  other 
types  of  service,  including  in  some  cases  even  passenger 
trains.    The  volume  of  fruit  and  vegetable  business  handled 
by  railroads  has  now  reached  enormous  proportions. 

380.  The  time  element. — After  the  grower,  the  picker,  the 
teamster,  the  grader,  the  packer,  and  the  car-loader  has  each 
done  his  part  hi  preparing  the  fruits  for  transit  or  storage,  the 
conditions  under  which  the  product  is  held  have  an  important 
influence  on  its  keeping  qualities.     The  time  required  to 
transport  the  packed  fruit  to  market  varies  from  a  few  days 
to  as  long  as  three  weeks,  during  which  a  very  considerable 
deterioration  may  occur  unless  special  conditions  are  pro- 
vided to  prevent  it.     The  time  element  is  most  important  for 
the  soft  and  quick-ripening  fruits  such  as  berries,  cherries, 


268  HORTICULTURE  FOR  SCHOOLS 

peaches,  plums,  and  prunes,  and  least  significant  in  the  case 
of  the  harder  and  slow-ripening  sorts  such  as  apples,  some 
varieties  of  pears,  and  the  citrus  fruits. 

381.  The  temperature  element. — Next  to  the  type  of 
handling  given  the  fruits,  the  most  important  factor  in  their 
sound  transportation  to  market  and  storage  is  the  tempera- 
ture at  which  they  are  held.     As  warmth  favors  decay,  cold 
checks  it.    The  temperature  factor  is  very  important  for  all 
fruits,  but  it  would  be  impossible  to  transport  the  soft  fruits 
to  market  without  some  means  of  cooling  and  keeping  them 
cool  during  the  trip.     This  is  the  purpose  of  the  modern 
refrigerator-car. 

382.  History  of  refrigeration. — The  refrigerator-car  was 
invented  in  the  middle  of  the  last  century  but  did  not  come 
into  general  use  until  the  decade  beginning  1870.     During 
these  ten  years  the  meat-packers  and  shippers  adopted  the 
car  very  generally,  and  in  the  next  decade,  from  1880  to  1890, 
the  shippers  of  fruit  followed  their  example. 

At  first  objections  were  raised  to  the  building  of  these 
expensive  cars  on  the  ground  that  they  could  be  used  for  a 
limited  time  only  in  each  year.  This  has  not  proved  to  be  the 
case.  The  season  for  perishable  products  opens  in  the  United 
States  in  Florida  in  late  winter.  The  railroads  estimate  that 
it  then  moves  northward  as  the  season  advances  at  the  rate 
of  about  fifteen  miles  a  day.  Meanwhile  the  refrigerator-car 
follows  this  advancing  season  and  is  used  to  haul  the  fruit 
from  each  section  successively.  Finally,  the  cars  which  were 
employed  in  the  beginning  of  the  season  to  haul  the  fruit  from 
Florida  northward,  are  used  later  to  carry  the  northern  prod- 
ucts southward.  It  has  now  been  found  that  in  addition 
to  keeping  the  fruit  cool,  these  cars  can  be  used  during  the 
fall  and  winter  in  the  North  for  the  transportation  of  products 
which  otherwise  would  be  frozen  by  the  extreme  cold.  The 
same  construction  which  in  summer  excludes  the  heat  is 
utilized  in  the  winter  to  keep  the  warmth  in  the  car. 


MARKET  PREPARATION,  TRANSPORTATION,  STORAGE  269 

383.  The  refrigerator-car  consists  of  an  insulated  com- 
partment at  the  ends  of  which  ice  is  stored.     In  cooler 
weather,  when  ice  is  not  being  used,  ventilators  at  the  ends 
of  the  car  are  left  open.     In  refrigeration,  the  cooling  of 
the  fruit  is  accomplished  by  the  circulation  of  air.     The 
cold  air  about  the  ice  in  the  bunkers,  being  heavier  than  the 
warmer  air  in  the  body  of  the  car,  sinks  down  and  flows  out- 
ward along  the  floor,  displacing  the  warmer  air,  which  rises 
and  gradually  moves  along  the  ceiling  to  the  ice  bunkers 
where  it  is  cooled  and  passes  downward.    Thus  there  is  a 
continuous  air  circulation  downward  through  the  ice  bunkers 
and  upward  among  the  tiers  of  fruit  packages.    The  cooling 
capacity  of  the  air  is  greatest  at  the  bottom  of  the  car,  and 
diminishes  as  the  air  passes  upward.    As  the  air  circulation 
is  due  solely  to  the  difference  in  density  or  weight  of  the  cold 
air  columns  within  the  ice  bunkers  and  the  warmer  air  in  the 
body  of  the  car,  the  movements  of  the  air  currents  are  sluggish 
and,  therefore,  do  not  cool  the  fruit  quickly,  especially  if 
there  is  any  considerable  heat  leakage  into  the  car.     The 
amount  of   heat  leakage  is  determined   primarily  by  the 
efficiency  of  the  insulation  but  this  is  not  of  the  highest  type, 
owing  to  limitations  of  cost  and  weight  in  car  construction. 
The  leakage  is  naturally  greatest  when  the  difference  in  tem- 
perature within  and  without  the  car  is  at  a  maximum.    It  is 
impossible  to  prevent  this  leakage  entirely  even  with  the 
best  insulation  and  car  construction  now  in  use. 

384.  Limitations. — The  refrigerator-car  is  not  to  be  con- 
sidered in  the  same  class  with  the  cold  storage  warehouse 
plant.    The  insulation  is  not  as  efficient  and  the  methods  of 
stacking  and  piling  the  fruit  are  such  that  there  is  serious 
interference  with  the  circulation  of  the  air  within  the  car. 
Moreover,  the  refrigerating  medium  (usually  ice  alone)  is  not 
as  efficient  as  the  material  used  in  mechanically  cooled  ware- 
house plants.    For  these  reasons,  the  temperature  within  the 
refrigerator-car  is  not  as  uniform  as  is  necessary  for  the  safe 


270  HORTICULTURE  FOR  SCHOOLS 

carrying  of  fruits  for  any  considerable  length  of  time.  More- 
over, a  high  consumption  of  ice  is  needed  to  offset  the  un- 
avoidable heat  leakage. 

When  the  fruit  is  packed  and  loaded  into  the  car  while 
warm,  there  is  a  very  considerable  variation  in  the  temper- 
ature conditions  in  different  parts  of  the  carload.  The 
warmer  air  rises  to  the  top  of  the  car,  and  accumulates  in  a 
layer  which  extends  far  enough  down  to  affect  the  upper  tiers 
of  packages.  It  is  cool,  of  course,  but  not  to  the  same  degree 
as  the  air  below.  For  this  reason,  perishable  produce  cannot 
be  loaded  to  the  full  height  of  the  car.  Frequently  in  the 
case  of  quick  ripening  fruits,  the  packages  on  the  upper  tiers 
arrive  in  market  with  considerable  deterioration  due  to  over- 
ripeness  and  decay,  while  those  in  the  bottom  tiers  arrive  in 
sound  condition. 

The  limitations  of  refrigeration  have  led  to  attempts  to 
cool  the  fruit,  or  the  air  in  the  car  or  both,  before  the  train 
starts  on  its  way.  Experiments  in  precooling  were  conducted 
by  the  United  States  Department  of  Agriculture,  with  results 
that  seemed  very  satisfactory,  and  this  process  is  now  being 
practiced  with  oranges.  Attempts  to  precool  other  fruits  have 
not  proved  as  satisfactory,  but  it  is  probable  that  in  the  future 
practical  and  inexpensive  methods  will  be  devised. 

385.  Storage  consists  in  placing  products  under  favorable 
conditions  for  continuing  their  life  activity  slowly  and  thus 
prolonging  their  life  span.  Storage  may  be  carried  on  accord- 
ing to  either  of  two  ways : 

(1)  Cold  storage  consists  in   holding   compartments   or 
rooms  cool  by  special  means,  to  the  lowest  possible  tempera- 
ture that  will  keep  the  fruit  in  good  condition.    This  tempera- 
ture is  usually  32  degrees. 

(2)  Common  storage,  sometimes  called  dry  storage,  consists 
of  storing  in  special  rooms  or  plants;  the  process  depends  on 
ventilation  to  cool  the  fruit  and  hold  it  in  good  condition  for 
a  longer  period  than  the  normal  season.    There  is  no  artificial 


MARKET  PREPARATION,  TRANSPORTATION,  STORAGE  271 

cooling  in  this  method.  The  fruit  cannot  be  held  so  long  or 
in  such  good  condition  and  the  process,  therefore,  is  ordinarily 
not  so  good  as  cold  storage.  Even  though  the  temperature 
at  which  the  fruit  is  kept  in  common  storage  is  fairly  satis- 
factory, the  cooling  is  done  much  more  slowly  than  in  cold 
storage  and  this  results  in  quicker  deterioration. 

386.  Essentials  of  success  in  cold  storage. — Certain 
essentials  must  be  observed  if  fruit  in  cold  storage  is  to  be 
kept  successfully  for  any  considerable  length  of  time.  The 
stored  fruit  must  be  well  grown  and  of  good  quality  or  it  will 
not  last;  besides,  cold  storage  is  expensive  and  it  does  not 
pay  to  subject  any  but  the  best  quality  of  fruit  to  such  a 
process.  Bruises  or  abrasions  of  the  skin  obtained  in  picking 
or  packing  persist  in  storage  and  allow  decay  to  get  a  start. 
If  this  does  not  become  manifest  while  the  produce  is  still  in 
storage,  it  will  do  so  immediately  after  it  is  taken  out.  If  the 
material  to  be  stored  was  in  poor  condition  when  placed  in 
the  warehouse  it  will  be  much  poorer  when  it  is  removed. 
On  the  other  hand,  if  it  was  in  good  condition  and  the  storage 
facilities  are  satisfactory,  the  chances  are  that  it  will  be  in 
first-class  shape  when  removed. 

If  perishable  goods  are  to  be  kept  in  storage  for  any  length 
of  time,  it  is  desirable  that  they  be  placed  there  at  the  earliest 
possible  moment.  It  is  well  known,  for  example,  that  a  delay 
of  ten  days  in  the  storing  of  apples  may  reduce  the  storage 
period  from  one  to  three  months. 

There  is  a  limit  also  to  the  length  of  time  that  fruit  can  be 
held  successfully  in  storage.  It  is  necessary  in  this  connec- 
tion to  inspect  the  product  carefully  from  time  to  time  and 
to  withdraw  it  from  storage  as  soon  as  it  shows  indication  of 
deterioration. 

It  is  never  practical  to  re-store.  Fruit  which  has  once  been 
warmed  up  after  it  has  been  in  storage  has  poor  keeping 
qualities  and  would  deteriorate  very  quickly  even  though 
placed  again  at  a  low  temperature.  It  is  also  true  that  fruit 


272  HORTICULTURE  FOR  SCHOOLS 

does  not  keep  long  after  withdrawal.    It  is,  therefore,  desir- 
able to  sell  or  dispose  of  it  in  other  ways  as  soon  as  possible. 

387.  Care  of  storage-rooms. — It  is  essential  that  storage- 
rooms  be  kept  clean  and  dry.    Strong  odors  are  readily  ab- 
sorbed by  materials  in  storage  and,  therefore,  fish,  onions, 
citrus  fruits,  eggs,  celery,  and  similar  products  should  not  be 
kept  promiscuously  in  the  same  room.    Fluctuations  of  tem- 
perature are  exceedingly  injurious  and  should  be  avoided. 
Cold  storage  companies  have  a  regulation  that  rooms  cannot 
be  opened  except  at  stated 'intervals.    Cold  storage  plants 
must  be  so  constructed  that  they  are  well  insulated  against 
the  entrance  of  heat  and  must  be  provided  with  adequate 
facilities  for  reducing  the  temperature  to  the  point  desired. 
If  the  thermometer  drops  too  low,  the  commodity  in  storage 
will  be  injured  perhaps  even  more  seriously  than  if  the  tem- 
perature is  too  high.    Theoretically,  this  temperature  should 
be  as  near  the  freezing  point  of  the  product  as  possible  with- 
out actually  freezing.    The  standard  cold  storage  temperature 
for  fruits  is  32  degrees  F.,  but  there  are  some  exceptions. 
For  example,  citrus  fruits  are  stored  at  a  temperature  from 
50  to  55  or  even  as  high  as  60  degrees,  and  some  varieties  of 
apples  are  best  kept  at  35  degrees.     In  transportation  it 
would  be  desirable,  if  possible,  to  have  the  same  temperature, 
but  it  is  impracticable  to  hold  cars  so  low  on  account  of  the 
expense  involved.     The  average  temperature  of  the  refrig- 
erator-car is  not  far  from  40  degrees. 

It  might  be  supposed  that  a  temperature  of  32  degrees, 
which  is  the  freezing  point  of  water,  would  injure  all  fruit. 
This  is  not  the  case,  for  fruit  juices  contain  various  substances 
in  solution  which  have  the  effect  of  lowering  their  freezing 
point.  A  solution  of  water  and  sugar  will  freeze,  not  at  32 
degrees,  but  at  a  temperature  several  degrees  lower.  The 
same  is  true  of  fruit  juices. 

388.  Advantage  of  storage. — The  storage  of  fruits  is  of 
advantage  in  several  ways.     It  takes  care  of  a  surplus  which 


MARKET  PREPARATION,  TRANSPORTATION,  STORAGE  273 

would  otherwise  be  thrown  on  markets  carrying  already  the 
maximum  which  the  consuming  public  will  buy.  It  is  a  bene- 
fit to  the  consumer  because  it  enables  him  to  purchase  perish- 
able products  out  of  season  at  reasonable  prices.  When  carried 
on  in  connection  with  transportation,  it  makes  possible  the 
shipment  of  fruit  and  vegetables  for  long  distances  at  a  com- 
paratively slight  increase  in  cost. 

Storage  plays  a  double  role  in  distribution;  it  widens  the 
field  and  extends  the  time.  The  present  commercial  develop- 
ment of  industries  dealing  in  perishable  or  semi-perishable 
products  would  not  be  possible  without  storage. 

EXERCISES 

EXERCISE  I. — The  packing  of  fruit. 

Materials. — Boxes  or  crates  of  fruit  such  as  apples,  oranges,  or  other 
fruit  packed  ready  for  the  market. 

Procedure. — Open  the  box  before  the  class  and  have  the  pupils 
make  a  diagram  of  each  layer  as  it  is  removed  until  the  box  is  empty. 
Then  have  members  of  the  class  replace  the  layers,  using  the  diagrams 
which  they  have  previously  made. 

EXERCISE  II. — Field  trip  to  markets. 

Procedure. — Make  a  study  at  different  markets  of  fruit  as  it  appears 
on  the  stand.  Note  the  general  condition  of  the  fruit,  the  pack,  the 
container,  the  label,  the  point  of  origin,  attractiveness  of  display. 

Each  student  should  write  a  paper  for  his  note-book  based  on  obser- 
vation on  this  trip. 

EXERCISE  III. — Balling  test  for  ripeness  of  grapes. 

Materials. — Balling  saccharimeter,  glass  cylinder,  sample  of  grapes, 
muslin  cloth,  glass  beaker. 

Procedure. — Squeeze  grapes  in  muslin  cloth  and  collect  juice  in  glass 
beaker.  Pour  this  juice  into  the  glass  cylinder  until  there  is  sufficient 
to  float  the  saccharimeter.  Note  saccharimeter  reading  together  with 
temperature  correction.  Make  correction  as  indicated  on  the  sac- 
charimeter and  record  in  your  note-book  the  corrected  saccharimeter 
reading. 

Grapes  for  the  fresh  fruit  market  should  contain  at  least  16  or  17 
per  cent  of  sugar  and  those  for  raisins  24  to  25  per  cent.  How  does 
this  sample  compare  with  the  requirement? 


274  HORTICULTURE  FOR  SCHOOLS 

EXERCISE  IV. — Eight-to-one  test  for  ripeness  of  oranges. 

Materials. — Brix  spindle  graduated  in  tenths,  beaker,  centigrade 
thermometer,  glass  cylinder  to  hold  Brix  spindle,  10  or  25  c.c.  pipette, 
one  burette  and  support;  one  liter  standard  alkali  solution,  1  ounce 
indicator  solution,  lemon  squeezer,  large  glass  or  granite  cup,  straining 
cloth  or  wire  strainer. 

Procedure. — Take  a  sample  of  nine  to  twelve  oranges,  cutting  them 
in  half.  Extract  juice  with  lemon  squeezer  and  strain.  Introduce 
juice  into  glass  cylinder  until  there  is  sufficient  to  fill  the  cylinder. 
Take  spindle  reading  (being  careful  to  write  this  down)  together  with 
temperature.  From  the  table  obtain  temperature  correction  and  add 
or  subtract  to  Brix  reading  as  case  may  be.  This  corrected  reading 
indicates  the  percentage  of  soluble  solids  present  in  the  orange  juice. 

Next  dbcermine  acid  present  as  follows:  Draw  off  10  or  25  c.c.  of 
juice  into  a  clean  glass  beaker.  Add  some  distilled  water  and  several 
drops  of  indicator.  Pour  standard  alkali  solution1  into  the  burette 
until  the  upper  end  of  the  alkali  column  is  on  the  zero  mark.  Now  add 
alkali  solution  to  the  orange  juice,  at  first  gradually  and  finally,  drop 
by  drop,  until  a  permanent  pink  color  appears.  Note  the  reading  of 
the  burette.  Multiply  this  reading  by  ten  and  you  have  the  milligrams 
of  acid  present  in  the  sample  of  juice.  Next,  change  cubic  centimeters 
of  juice  to  milligrams  of  juice  by  multiplying  by  1000  and  the  specific 
gravity.  This  can  be  found  by  following  the  directions  under  Table  II. 
To  obtain  the  percentage  of  acid  present,  multiply  milligrams  of  acid 
by  100,  then  divide  by  milligrams  of  juice.  Now  divide  the  percentage 
of  soluble  solids  by  the  percentage  of  acid  and  the  answer  is  the  ratio. 

E.  g.  Suppose  that  the  Brix  reading  is  12.6,  temperature  13°  "C," 
cubic  centimeters  of  juice  25,  and  of  standard  base  necessary  to 
neutralize  the  juice,  36.  The  problem  is  worked  as  follows: 

Correction  for  13  is  .2.  This  is  to  be  subtracted.  12.6  minus  .2 
equals  12.4.  This  answer  represents  the  percentage  of  soluble  solids 
in  the  orange  juice.  The  specific  gravity  of  the  solution  with  a  test 
of  12.4  is  1.05021.  The  weight  of  25  c.c.  of  juice  is  found  by  multiplying 
this  figure  by  the  specific  gravity:  25X1.05021  equals  26.25525  grams. 
Change  to  milligrams  by  multiplying  by  1000;  this  equals  26,255.25. 
Multiply  36X10  and  X100  equals  36,000.  Divide  this  by  26,255.25 
equals  1.37+-  This  is  the  percentage  of  acid  in  the  juice.  Divide  the 
percentage  of  soluble  solids  (12.4)  by  the  percentage  of  acid  (1.37); 
this  equals  9.05  and  the  ratio  is  9.05  to  1. 

»To  prepare  standard  solution,  dissolve  6.25  gm.  sodium  hydroxide 
in  enough  distilled  water  to  make  a  liter  of  solution. 


MARKET  PREPARATION,  TRANSPORTATION,  STORAGE  275 

TABLE  I 
All  corrections  given  below  are  to  be  subtracted  from  the  Brix  reading: 

TEMPERATURE  (DEGREES  "c")         CORRECTION 

0  .46 

5  .40 

10  .31 

11  .27 

12  .23 

13  .20 

14  .16 

15  .13 

16  .08 

17  .03 

All  corrections  given  below  are  to  be  added  to  the  Brix  reading: 

18  .03 

19  .08 

20  .16 

21  .23 

22  ,30 

23  .36 

24  .42 

25  .48 

EXERCISE  V. — The  principle  of  refrigeration. 

Materials. — Two  glass  beakers,  small  bottle  of  ether,  25  c.c.  of  water, 
1-200  c.c.  flask. 

Caution. — Do  not  allow  a  flame  of  any  sort  in  the  vicinity  of  ether! 
It  is  highly  explosive! 

Procedure.1 — Pour  the  water  into  the  flask  and  with  this  held 
slanting  in  the  hand,  pour  ether  over  the  outside  into  the  other  beaker. 
Then  pour  the  ether  from  this  beaker  again  over  the  flask  into  the  first 
beaker.  Continue  the  process  until  the  water  in  the  flask  is  frozen. 

Ether  evaporates  very  readily.  When  it  does  so  it  absorbs  heat 
from  the  flask.  This  causes  the  water  to  freeze. 

The  same  process  takes  place  in  a  refrigerator  plant  except  that  in 
this  case  ammonia  which  is  very  much  cheaper  than  ether  is  utilized. 
The  ammonia  extracts  heat  from  a  solution  of  salt  and  water  and  this 
cold  brine  is  then  circulated  through  pipes  which  are  located  in  the 
cold  storage-rooms. 

1  If  the  quantity  of  material  available  is  small  or  if  the  room  is  close,  this 
had  better  be  performed  as  an  instructor's  experiment. 


276 


HORTICULTURE  FOR  SCHOOLS 


TABLE  II 


Degree 
Brix 
(Per  Cent 
Sugar,  etc.) 

Specific 
Gravity 

Degree 
Brix 
(Per  Cent 
Sugar,  etc.) 

Specific 
Gravity 

Degree 
Brix 
(Per  Cent 
Sugar,  etc.) 

Specific 
Gravity 

9.0...  . 

.1.03599 

11.4..  . 

.  .  1.04599 

1Q  0 

1  0^617 

.1..  .  . 
.2.  .  .  . 

.1.03640 
.1.03682 

.5... 
.6... 

.  .1.04641 
.  .1.04683 

.9.... 
14.0  

.    .05660 
.    .05703 

.3.... 

.1.03723 

.7... 

,.1.04726 

i 

0^746 

.4.... 
.5.... 
.6.... 

.1.03765 
.  1.03806 
.1.03848 

.8..  . 
.9... 
'  12.0... 

.  .1.04768 
.  .1.04810 
..1.04852 

.2.... 

.3.  .  .  . 

4 

.    .05789 
.   .05874 
i  (KQ17 

.7.  .  .  . 

.   .03889 

.1     . 

.  .1.04894 

i  o^QftO 

.8.    . 

.    .03931 

2 

1.04937 

i  fjfinn4? 

.9.  .  .  . 
10.0.  .    . 

.    .03972 
.    .04014 

.3... 
.4  .  . 

..1.04979 
.  .1.05021 

.7..  .. 

.1.06047 

1  AfiftQO 

.1  

.04055 

.5 

1.05064 

flRIQQ 

.2.... 

.1.04097 

.6... 

..1.05106 

1^0 

06176 

.3.... 

.1.04139 

.7... 

.  .1.05149 

.1..  .. 

.    .06219 

.4.... 
.5.... 

.1.04180 
.1.04222 

.8... 
.9... 

..1.05191 
..1.05233 

.2.... 
.3     . 

.    .06262 
.06306 

.6.... 

.1.04264 

13.0... 

..   .05276 

4 

0634Q 

.7.  .  .  . 

.1.04306 

.1  .  . 

.05318 

ACOQO 

.8.  .  .  . 
.9.  .  .  . 

.1.04348 
.1.04390 

.2... 
.3... 

..   .05361 
..   .05404 

.6..  .. 
.7     . 

.   .06436 
.06479 

11.0.... 

.1.04431 

.4     . 

.   .05446 

1  Ofi^99 

.1.... 
.2.... 
.3..  .. 

.1.04473 
.1.04515 
.1.04557 

.5... 
.6... 
.7.  .  . 

..1.05489 
..1.05532 
1.05574 

.9.... 
16.0.... 

.1.06566 
.1.06609 

To  obtain  specific  gravity,  first  find  Brix  reading,  then  make  correc- 
tion for  temperature;  then  take  next  reading  found  in  the  left  hand 
column  of  figures  in  table  above  and  note  opposite  the  specific  gravity 
in  the  right  hand  column.  E.  g.  If  the  Brix  reading  is  11.4  and  if  the 
temperature  is  22°  "C.,"  then  the  temperature  correction  is  .3  and  this 
correction  is  to  be  added.  Adding  .3  to  11.4  gives  11.7  and  the  specific 
gravity  for  orange  juice  whose  Brix  reading  is  11.7  is  1.04726. 

EXERCISE  VI. — Cold  storage. 

Procedure. — If  there  is  a  cold  storage  plant  within  a  reasonable 
distance  of  the  school,  the  class  should  visit  it,  noting  such  points  as 


MARKET  PREPARATION,  TRANSPORTATION,  STORAGE  277 

the  following:  Size,  cost,  method  of  cooling,  products  stored,  length 
of  time  they  have  been  in  storage,  general  condition,  cost  of  storage, 
regulations  regarding  withdrawal,  benefits  to  producers,  benefits  to 
consumers,  state  laws  governing  cold  storage.  Notes  should  be  taken 
on  the  trip  and  this  should  be  followed  by  a  discussion  the  following 
day  in  class,  after  which  each  student  should  write  up  a  complete 
account  for  his  note-book. 


CHAPTER  XIX 
MARKETING 

THE  preparation  for  market  and  transportation  normally 
precede  the  marketing  and  selling  stage.  But  this  is  not  al- 
ways the  case.  Sometimes  the  fruit  is  sold  on  the  trees  or 
sales  may  be  local,  to  country  merchants,  or  direct  to  the 
consumer.  Sales  direct  to  the  consumer  are  by  house-to- 
house  peddling,  or  through  the  public  markets.  Sales  to 
distant  points  may  be  made  f.  o.  b.  shipping  point,  which 
means  that  the  buyer  pays  the  freight;  or  they  may  be  on 
the  " delivered"  basis,  where  the  shipper  pays  transportation 
charges. 

Some  of  the  common  agencies  in  the  marketing  process 
will  be  considered  in  the  following  pages. 

389.  Commission-men. — Sometimes  fruit  is  handled  on 
the  commission  basis.  That  is,  it  is  shipped  by  the  producer 
to  an  individual  or  a  firm  in  a  large  city  to  be  sold  in  consider- 
ation of  a  certain  fixed  percentage  of  the  selling  price.  The 
commission-man  generally  sells  direct  to  the  retailers,  that 
is,  to  the  stores,  venders,  peddlers,  and  the  like,  and  occasion- 
ally through  an  auction  company.  The  fruit  does  not  at  any 
time  become  the  property  of  the  commission-man  but  is 
handled  by  him  as  an  agent  for  the  grower.  He  sells  the 
fruit,  collects  the  money,  and  remits  the  sale  price,  minus 
the  commission,  to  producer.  There  has  been  a  large  amount 
of  dissatisfaction  with  this  system.  The  opportunities  for 
dishonesty  are  very  great,  because  the  grower  finds  it  almost 
impossible  to  keep  a  check  on  either  the  condition  or  the 
disposition  of  his  fruit.  The  commission  business  as  a  whole 

278 


MARKETING  279 

has,  therefore,  fallen  into  disrepute.  Many  commission 
houses,  on  the  other  hand,  have  built  up  for  themselves  repu- 
tations for  honesty  in  all  their  dealings  which  have  enabled 
them  to  continue  despite  the  growing  suspicion  concerning 
the  commission  business  as  a  whole.  Furthermore,  many 
farm  products,  especially  fruits  and  melons,  are  of  such  per- 
ishable nature  that  dealers  in  the  city  are  unwilling  to  receive 
them  by  outright  purchase.  They  insist  that  the  risk  be 
assumed  by  the  shipper,  and  this  leaves  the  commission 
method  almost  the  only  alternative.  There  has  been  a  tend- 
ency in  recent  years  to  pass  laws  subjecting  the  commission- 
men  to  rigid  accounting  in  all  their  dealings  both  with  pro- 
ducer and  retailer,  and  the  effect  will  unquestionably  result 
in  good,  alike  to  the  producer  and  to  the  honest  commission- 
man. 

390.  The  broker. — A  broker  differs  from  a  commission- 
man  in  that  he  deals  in  large  quantities,  and  has  regular 
customers  among  both  buyers  and  sellers.  He  is  located,  as 
a  rule,  in  a  large  city,  where  he  becomes  thoroughly  ac- 
quainted with  market  conditions,  thus  being  able  to  sell  the 
produce  at  the  best  figure.  He  does  so  in  the  name  of  the 
shipper,  receiving  a  fixed  compensation  for  his  services.  The 
shipper  is  sometimes  the  producer  and  sometimes  a  local 
buyer  or  speculator,  who  may  or  may  not  have  bought  the 
fruit  on  the  trees.  The  broker's  compensation  is  usually  so 
much  for  the  car,  box,  or  crate.  This  method  of  sale  usually 
works  out  satisfactorily  for  all  concerned  but  is  limited,  as  a 
rule,  to  the  larger  shippers.  Ordinarily  the  broker  sells  to 
the  jobber. 

»391.  The  jobber  buys  in  large  quantities  from  the  pro- 
ducer, a  local  buyer,  or  through  a  broker,  and  sells  to  the 
retail  trade.  The  jobber  is  necessary  under  the  present 
marketing  system  because  he  breaks  up  the  large  lots.  In 
doing  so,  he  assumes  a  number  of  responsibilities:  (1)  He 
guarantees  to  the  shipper  payment  for  the  fruit  received. 


280  HORTICULTURE  FOR  SCHOOLS 

(2)  He  sees  to  it  that  transportation  is  supplied  for  delivering 
the  fruit  to  the  retail  stores.  This  calls  for  a  well-developed 
delivery  system  in  the  large  cities,  for  the  retail  stores  buy 
frequently  and  in  small  quantities.  (3)  The  jobber  becomes 
an  expert  in  brands  of  fruit  received  from  different  sections 
of  the  country  and  from  separate  packing-houses  in  the  same 
region.  Very  frequently  these  brands  are  demanded  year 
after  year  by  certain  retail  stores;  the  jobber  thus  acts  for 
them  in  seeing  that  a  constant  supply  of  the  products  desired 
is  always  on  hand. 

392.  Sale  by  auction. — In  seventeen  of  the  large  cities 
of  the  United  States,  one  or  more  auction  markets  are  main- 
tained for  the  sale  of  fruit.    These  have  come  to  play  a  very 
important  part  in  establishing  fruit  prices  throughout  the 
country.    In  the  main,  the  fruits  sold  at  auction  are  those 
which  will  not  stand  storage  for  any  great  length  of  time. 
The  auction  market  acts  quickly.    Fruit  is  received  by  the 
carload  and  enough  boxes  opened  and  examined  to  give  a 
fair  idea  of  the  contents  of  the  car.    The  carload  is  then  sold 
to  the  highest  bidder.     This  method  cannot  be  successful 
unless  there  is  a  large  quantity  of  fruit  on  hand  regularly, 
of  a  given  kind  and  standardized  to  an  extent  that  will  indi- 
cate rather  definitely  the  quality  of  the  commodity.    These 
conditions  alone  will  attract  the  large  number  of  bidders 
necessary.    This  method  of  sale  is  not  adapted  to  the  small 
shipper  who  sends  his  fruit  at  irregular  intervals.    Auction 
markets  sell  to  jobbers  and  retailers. 

393.  Defects  in  the  marketing  system. — The  same  lot  of 
fruit  frequently  goes  through  the  hands  of  many  dealers  of 
one  sort  or  another  before  it  reaches  the  consumer.     The 
charge  is  often  made  that  there  are  too  many  middle-men, 
each  demanding  a  profit  from  the  handling  of  the  fruit,  and 
that  the  system  results  in  a  high  price  to  the  consumer  and  a 
low  return  to  the  producer.     The  tendency  to  consider  all 
the  profits  to  middle-men  as  unearned  is  hardly  fair.     The 


MARKETING  281 

middle-men  are  searching  for  channels  by  which  fruit  can  be 
put  before  the  potential  consumer.  They  hold  and  finally 
transfer  fruit  to  points  where  it  seems  to  be  in  demand, 
usually  buying  in  large  quantities  and  selling  in  smaller. 
If  a  dozen  middle-men  handle  produce  more  cheaply  than 
could  one  or  finally  find  a  market  for  what  otherwise  might 
be  wasted,  there  is  justification  for  each  of  the  twelve.  But 
that  a  great  deal  of  confusion  and  waste  exists  under  the 
present  system  is  undeniable.  Moreover,  from  time  to  time 
abuses  of  the  system  have  arisen  and  have  threatened  the 
growers  very  gravely.  Sometimes  buyers  have  combined  to 
agree  on  a  maximum  price  to  be  paid  the  growers,  with  the 
result  that  all  the  fruit  had  to  be  sold  at  a  low  price,  and 
sometimes  jobbers  have  combined  to  contract  for  all  the 
space  in  warehouses  of  large  cities.  Commission-men  have 
been  known  to  repack  products  into  more  boxes  than  the 
growers  used,  returning  the  proceeds  for  the  original  number 
to  the  producer  and  keeping  for  themselves  the  profit  from 
the  extra  boxes  thus  obtained.  Commission-men  and  brokers 
themselves  have  turned  jobbers,  and  while  extracting  from  the 
public  the  maximum  prices  have  returned  to  the  grower  the 
minimum. 

394.  Cooperation. — When  the  present  marketing  system 
has  given  the  farmer  a  fair  return  on  his  investment,  he  has 
shown  himself  reluctant  to  turn  to  other  methods.     When 
for  any  reason  this  system  has  failed,  growers  have  sought 
protection  through  the  passage  of  laws  (such  as  those  re- 
stricting the  action  of  railroads  and  commission-men)  and 
through   organization    into    cooperative   societies.      A    co- 
operative organization  is  a  combination  for  mutual  benefit 
of  individuals  engaged  in  similar  work  or  business. 

395.  Essentials  for  success  in  cooperative  marketing. — 
Since  the  cooperative  organization  has  for  its  purpose  the 
benefit  of  all  its  members,  it  is  necessary  that  the  problems 
and  needs  of  its  constituency  be  alike,  in  order  that  what  will 


282  HORTICULTURE  FOR  SCHOOLS 

benefit  one  will  necessarily  serve  all.  The  successful  co- 
operative organizations  have  been  those  which  have  confined 
themselves  to  one  crop  or  to  one  particular  line  of  activity. 
For  example,  an  organization  -for  the  marketing  of  poultry 
should  not  attempt  to  engage  in  handling  apples;  dried 
fruits  should  be  kept  separate  from  fresh  ones;  and  citrus 
fruits  from  those  of  the  deciduous  varieties .  The  crop  handled 
by  any  one  organization  should  be  of  about  the  same  kind  and 
quality  and  produced  under  somewhat  similar  conditions. 

The  second  essential  is  that  the  membership  be  held 
together  by  the  strongest  possible  ties.  The  first  of  these  is 
the  bond  of  a  common  necessity.  Where  the  cooperative 
organization  has  not  filled  an  imperative  need,  it  has  proved 
a  failure.  The  necessity  may  arise  from  lack  of  marketing 
facilities  on  account  of  geographical  location  or  other  cir- 
cumstances over  which  the  grower  has  no  control.  It  may 
result  from  collusion  among  buyers,  whereby  the  grower  is 
prevented  from  receiving  a  fair  rate  for  his  product.  It  may 
be  due  to  unequal  distribution  of  the  product  which  results 
in  the  growers  competing  one  with  the  other  for  the  market 
to  the  detriment  of  all.  There  may  be  need  for  the  reduction 
of  cost  of  handling,  for  this  is  sometimes  the  determining 
factor  in  the  success  of  an  horticultural  enterprise.  In  the 
case  of  many  agricultural  products,  an  increase  of  consump- 
tion is  necessary  which  the  individual  grower,  acting  by  him- 
self, is  unable  to  bring  about.  Again,  the  product  may  re- 
quire grading  and  packing  facilities  which  the  individual 
cannot  supply.  Whatever  the  need  for  cooperation  may  be, 
it  must  be  so  obvious  as  to  be  its  own  best  argument. 

Another  tie  which  helps  to  hold  the  members  of  a  co- 
operative association  together  is  that  of  mutual  confidence 
resulting  from  personal  acquaintance.  For  this  reason,  each 
community  should  preserve  its  individuality  and  not  go  too 
far  afield  in  the  selection  of  members.  Personal  association 
will  cause  each  member  to  feel  more  keenly  his  responsibility 


MARKETING  283 

to  the  others  in  times  of  stress  and  depression.  When  it  has 
seemed  desirable  to  organize  on  a  basis  larger  than  that  of 
the  neighborhood,  it  has  been  found  practicable  to  affiliate 
local  organizations  in  a  central  confederation. 

396.  Benefits. — A  cooperative  organization  may  perform 
many  services  for  its  members  and  the  public.    The  distribu- 
tion of  the  product  is  in  the  hands  of  the  producer  and  is  in 
his  interests.    The  organization  may  be  sufficiently  powerful 
to  hunt  out  new  markets  when  those  already  existing  are 
insufficient  for  the  product.    It  may  extend  the  marketing 
period  by  furnishing  its  members  adequate  storage  facilities 
for  perishable  products  until  such  time  as  the  regular  seasonal 
supply  has  disappeared.    It  may  reduce  the  cost  to  the  con- 
sumer by  delivering  the  product  in  good  condition  at  the 
time  and  place  it  is  needed  and  by  eliminating  many  inter- 
mediate  dealers.     It  may  standardize  pack  and  establish 
uniform  grades  so  that  buyers  can  be  assured  of  the  quality 
of  the  goods  they  are  purchasing  and  thereby  be  encouraged 
to  buy  in  larger  quantities  and  at  more  frequent  intervals. 
It  may  prevent  loss  through  disease  and  decay  by  making  a 
careful  study  of  each  phase  of  picking,  packing,  and  handling 
of  the  fruit  or  other  product.    Such  organizations  have  pre- 
vented exploitation  of  growers  by  shipping  companies,  mar- 
keting agencies  and  transportation  concerns,  and  have  pro- 
tected them  also  against  exorbitant  charges  by  the  warehouse 
interests. 

397.  Difficulties. — The  path  of  the  cooperative  organiza- 
tion is  strewn  with  difficulties.     It  must  be  democratic  in 
form  and  mode  of  operation  in  order  that  each  member  may 
feel  that  he  is  on  an  absolutely  equal  footing  with  every  other, 
and  that  there  are  no  secret  arrangements  whereby  one  mem- 
ber benefits  more  than  another.    At  the  same  time  enough 
power  must  be  given  the  leaders  of  the  organization  or  the 
manager  to  make  the  carrying  out  of  a  constructive  business 
program  possible,     The  choice  of  a  manager  is  always  a 


284  HORTICULTURE  FOR  SCHOOLS 

critical  step  in  the  progress  of  a  cooperative  organization. 
A  high  degree  of  integrity,  tact,  and  trained  executive  ability, 
is  required  for  the  successful  conduct  of  so  complex  a  business. 
The  organization  is  likely  to  be  subjected  to  considerable 
pressure  from  without.  Adverse  interests  encourage  members 
to  break  away  by  criticising  the  management  or  by  promising 
larger  returns  for  a  season  than  are  justified  by  the  condition 
of  the  industry.  There  is  always  a  certain  proportion  of  the 
membership  which  will  listen  to  such  propaganda  and  with- 
draw, leaving  the  brunt  of  the  fight  to  be  borne  by  those  who 
remain. 

398.  Extent  of  cooperative  marketing. — The  cooperative 
marketing  system  has  been  applied  successfully  to  many 
fields.    In  California,  cooperative  organizations  have  been 
formed  by  the  growers  of  citrus  fruits,  walnuts,  almonds,  lima 
beans,  celery,  and  cauliflower.     In  Maine,  Delaware,  and 
Maryland,  the  potato-growers  are  organized,  and  in  Colorado 
the  producers  of  cantaloupes.   The  fruit-growers  of  the  North- 
west have  organized  in  groups  according  to  the  kind  of  fruit 
raised.    In  Minnesota  the  shippers  of  live-stock  are  organized. 
The  list  of  cooperative  associations  is  growing  rapidly  in 
all  parts  of  the  United  States. 

399.  An  example  of  cooperative  marketing. — One  of  the 
largest  cooperative  organizations  in  the  United  States  is  the 
California  Fruit  Growers'  Exchange   (see   Figs.   134,     35), 
which  handles  the  orange  and  lemon  crop.    The  organization 
markets  the  fruit  of  eleven  thousand  growers.    These  pro- 
ducers are  separated  into  one  hundred  ninety-seven  neighbor- 
hood associations,   each   of  which  owns  a  packing-house. 
These  are  in  turn  organized  into  twenty  district  exchanges 
and  these  again  are  affiliated  in  one  central  organization, 
whose  place  of  business  is  in  the  city  of  Los  Angeles. 

The  exchange  has  as  its  field  of  operation  the  whole  of  the 
United  States  and  many  parts  of  Canada.  It  must  be  in- 
formed of  the  market  situation  as  it  exists  from1  day  to  day 


MARKETING  285 

throughout  this  vast  territory.  To  do  this,  it  maintains 
seventy-seven  district  offices  which  are  in  touch  with  twenty- 
five  hundred  jobbers.  These  jobbers  in  turn  deal  with  three 
hundred  thousand  retailers  and  these  latter  furnish  California 
oranges  and  lemons  to  one  hundred  twenty-five  million  con- 
sumers in  the  United  States  and  Canada,  the  return  value  of 
whose  products  in  the  wholesale  markets  is  between  seventy- 
five  and  one  hundred  million  dollars. 

The  organization  furnished  supplies  to  its  members  amount- 
ing in  one  year  to  over  six  million  dollars.  It  has  purchased 
a  tract  of  timber  lands  aggregating  more  than  forty-one 
thousand  acres,  which  will  insure  a  supply  of  lumber  for  box 
shocks  sufficient  for  the  next  fifty  years.  It  maintains  an 
advertising  department  which  has  made  "Sunkist"  a  house- 
hold word  wherever  oranges  and  lemons  are  bought.  It  has 
organized  a  by-products  company  which  extracts  citric  acid 
and  other  valuable  by-products  from  worthless  lemons  and 
which  is  now  devising  ways  of  utilizing  all  fruit  of  good  quality, 
but  inferior  in  appearance,  in  such  manner  that  the  growers 
will  receive  a  maximum  return  for  the  product. 

In  addition  to  these,  the  traffic,  legal,  and  field  departments, 
each  in  its  own  particular  province,  secure  benefits  to  the 
growers  which  they  could  not  possibly  obtain  for  themselves. 

400.  Market  information. — The  California  Fruit  Grow- 
ers' Exchange  maintains,  as  already  indicated,  seventy-seven 
sales  offices  throughout  the  United  States  and  Canada. 
These  agents  must  each  day  collect  information  and  trans- 
mit it  to  the  central  office  in  Los  Angeles,  and  this  office 
in  turn,  on  the  basis  of  this  information,  directs  the  ship- 
ment of  its  fruit.  A  specimen  telegram  from  one  of  these 
eastern  points  to  the  central  office  in  Los  Angeles  will 
illustrate  the  sort  of  information  collected  each  day:  "Ship 
as  soon  as  possible  60/126s,  120/150s,  120/176s,  40/200s, 
40/216s,  20/250s,  Martha  Washington  Valencias,  $2.75. 
Rather  coarse  quality,  some  very  green  S.  A.  2938.  Overdue 


286 


HORTICULTURE  FOR  SCHOOLS 


and  not  arrived,  railroad  over  which  car  is  routed  cannot 
locate  A.  C.  G.  2366.  If  we  cannot  sell  tomorrow  where  shall 
we  divert  O  K  3003?  Temperature  50  degrees  above  zero, 
11  A.  M.  Weather  Bureau  predicts  favorable  weather." 
The  meaning  of  this  telegram  is  as  follows:  "Ship  to  this 


H,  000 


GROWERS 
4, 


ooooooooooooooooooooooooooooooooooooooo 

80OOOOOOOOOOOOOOOOOOOO  OOOOOOOOOOOO  OOOOO 
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOi 


I 

I 


I 

I 


00000060000000000000000000000006006  6  OO 
ooooooooooooooooooooooooooooooooooooooo 
oooo  oooo  ooooo  oooo  oooooooooooooooooooooooo 

l97 

LOCAL   ASSOCIATIONS 

0000000000*0000000000 

20 
DISTRICT    EXCHANGES 

CALIFORNIA-FRUIT  ^QGROWERS-EXCHANGE 


a  o  a  a  a  o  a  a  a  o  D  o  o  a  a  a  a  a  a  DO  a  a  o  a  a  a  a  o  a  a  a  a  a  a  a  aao 
aaaaoaaaaaooaaaoaaoaaooaoaaoaaoaaocioao 

X  DISTRICTS  X 

¥  850    Car  Markets  T 

KW.f/*y%&/ffif;/?tiW£M^^ 

:!:J«;i:ttVwvwvw«;Vi;»-ivv^-f        2,500        S&#ttf3&&&'$^ffil!^ffi 

^  JOBBERS  ^ 

i>JM<^M^IM4^"'V'300,000*"     i.,w.,.,:, 

%&&  RETAILERS  SM^-iv; 


United  States       I25,OOQpOQ.       Canada 
CONSUMERS 


Fio.    134. — Steps  in  distribution  of  fruit  by  the  California 
Fruit  Growers'  Exchange. 


MARKETING  287 

point  as  soon  as  possible,  sixty  boxes  of  oranges,  each  con- 
taining one  hundred  twenty-six  oranges  to  the  box,  one 
hundred  twenty  boxes,  each  containing  one  hundred  fifty 
oranges  .  .  .  these  oranges  to  be  of  that  particular  grade 
known  as  Martha  Washington  Valencias.  I  can  sell  these 
at  $2.75  per  box.  A  car  of  oranges  shipped  from  the  S.  A. 
(San  Antonio)  district  exchange  arrived  in  rather  poor  con- 
dition; most  of  the  fruit  was  green,  and  rather  coarse  in 
quality.  Car  No.  2366  from  the  A.  C.  G.  (Azusa-Covina- 
Glendora)  exchange  has  not  arrived  and  we  cannot  locate 
railroad  over  which  it  was  routed.  Car  No.  3003  from  the 
O.  K.  (Ontario-Cucamonga)  exchange  has  been  routed  to 
this  point;  if  we  cannot  sell  it  here,  to  what  other  city  shall 
we  divert  it?  Temperature  is  fifty  degrees  above  zero,  at 
eleven  o'clock  this  morning.  The  Weather  Bureau  predicts 
favorable  weather." 

Seventy-seven  telegrams  of  this  same  sort  are  received 
each  day  in  Los  Angeles  from  the  seventy-seven  different 
selling  organizations  stationed  throughout  the  United  States 
and  Canada.  On  the  basis  of  this  information,  the  sales 
office  in  the  exchange  in  Los  Angeles  sends  out  directions  to 
each  of  these  offices  telling  them  what  to  do  under  the  cir- 
cumstances, and  advises  them  of  any  fruit  which  may  be 
en  route  to  them.  Meanwhile,  copies  of  these  incoming  and 
outgoing  telegrams  are  sent  to  each  of  the  nineteen  district 
offices  in  southern  and  central  California  and  the  managers 
act  in  accordance  with  the  information  thus  received.  Thus, 
each  of  the  various  districts  of  California  is  kept  in  contact 
with  actual  market  conditions  throughout  the  country. 

401.  Cost  of  marketing. — There  has  been  much  specula- 
tion and  heated  controversy  regarding  the  cost  of  putting 
agricultural  and  horticultural  products  in  the  hands  of  the 
consumer.  At  present,  the  United  States  Government  has 
marketing  experts  engaged  in  collecting  information  along 
this  line,  and  within  a  few  years  probably  more  will  be 


288 


HORTICULTURE  FOR  SCHOOLS 


known  concerning  this  subject.  The  California  Fruit  Grow- 
ers' Exchange  has  been  collecting  information  since  December, 
1913,  and  its  results  are  shown  in  the  diagram  (Fig.  135).  To 
quote  the  language  of  the  exchange :  "  Our  agents  have  tabu- 
lated the  delivered  price  to  jobbers  of  oranges  of  varying 
sizes.  They  have  also  tabulated  the  price  at  which  the  leading 
jobbers  have  charged  the  retailers  and  then  determined  the 
price  which  the  retailer  charged  the  consumer.  They  have 


FREIGHT 
and  REFRIGERATION 

20.5 


FIG.   135. — Distribution  of  gross  proceeds  of  citrus  sales.    An 
analysis  of  what  becomes  of  the  consumers'  dollar. 

then  put  the  results  in  the  form  of  a  diagram  which  represents 
the  consumers'  dollar.  This  diagram  shows  what  has  become 
of  the  amount  paid  by  the  consumer." 

According  to  these  figures,  the  retailer  kept  33.4  cents  of 
each  dollar  which  he  received  in  the  year  1914;  in  1915  his 
share  was  28.1  cents,  in  1916,  25,  and  in  the  year  1917,  29.2 
cents.  The  jobbers'  margin,  as  shown  in  the  diagrams,  has 
varied  from  8.8  in  1915  to  9.9  cents  in  1916.  Freight  and 


MARKETING  289 

refrigeration  cost  21  cents  in  1914  and  18.9  in  1916.  During 
the  other  two  years,  the  figure  remains  between  these  two. 
The  sale  cost  which  represents  the  proportion  which  goes  to 
the  cooperative  organization  has  remained  each  year  as 
1.2  cents;  packing  7.3  cents  in  1914  and  6.4  in  1916.  Picking 
and  hauling  has  cost  about  2.2  cents  each  year.  The  fruit 
has,  therefore,  netted  the  growers  during  these  four  years 
the  difference  between  the  totals,  given  here  and  one  hundred. 
That  is,  of  the  dollar  which  the  consumer  paid,  the  grower 
received  25.9  cents  in  1914;  in  1915  his  share  was  34.6;  in 
1916  it  had  risen  to  38.9  and  in  1917  it  was  33.2  cents. 

It  should  be  remembered  in  connection  with  these  figures 
that  they  deal  with  a  very  perishable  product  which  is  mar- 
keted in  most  cases  several  thousands  of  miles  away  from  the 
point  where  it  was  grown  at  a  season  of  the  year  when  loss 
from  decay  is  likely  to  be  very  large. 

Studies  of  this  sort  have  a  great  value  in  determining  the 
exact  facts  regarding  the  cost  of  marketing  and  in  suggesting 
the  points  at  which  improvements  may  be  made.  Those 
phases  of  marketing  which  at  present  are  weak  may  in  this 
way  be  strengthened.  The  charge  of  profiteering  so  fre- 
quently made  can  be  proved  if  it  really  exists,  and  if  it  does 
not  the  marketing  organizations  will  be  freed  from  the  incubus 
of  an  undeserved  accusation. 


CHAPTER  XX 
INCIDENTAL  PRODUCTS 

A  BY-PRODUCT  is  some  substance  or  article  produced  in  the 
course  of  a  process  of  manufacture,  in  addition  to  the  prin- 
cipal product  or  material.  It  frequently  happens,  however, 
that  the  by-products  become  of  more  importance  than  the 
primary  substances  themselves.  There  is  hardly  a  line  of 
manufacturing  of  any  importance  which  does  not  yield  by- 
products; the  elimination  of  waste  is  one  of  the  great  prob- 
lems of  the  day. 

402.  Some  examples  of  by-products. — One  of  the  most 
interesting  fields  for  study  of  by-products  is  that  of  illumi- 
nating gas.    Tin's  is  ordinarily  obtained  by  heating  coal  in  a 
closed  retort.    The  heating  process  drives  off  a  large  number 
of  substances,  leaving  behind  the  solid  coke,  an  article  that 
has  become  exceedingly  important  in  many  fundamental  in- 
dustries.   Later,  in  the  process  of  purification  of  the  illumi- 
nating gas,  other  by-products  are  obtained,  such  as  ammo- 
nium sulfate,  which  is  used  as  a  fertilizer;  acetic  acid,  the 
substance  which  makes  vinegar  sour;   benzene  and  carbolic 
acid,  familiar  to  all;  the  cresols,  used  as  disinfectants;  picric 
acid,  one  of  the  most  important  materials  in  the  manu- 
facture of  explosives;    aniline,  the  source  of  the  best  dyes; 
and  asphalt,  used  in  paving  roads  and  streets.    The  list  is 
given  to  indicate  the  importance  of  utilizing  what  once  were 
considered  waste  products,  having  no  value  whatever. 

403.  By-products  in  horticulture. — The  record  of  achieve- 
ment already  indicated  in  the  illuminating  gas  industry  can 
be  repeated  in  many  other  fields.    In  horticulture  itself  there 

290 


INCIDENTAL  PRODUCTS  291 

are  great  possibilities.  There  are  produced  every  year 
millions  of  gallons  of  cider,  immense  quantities  of  jelly 
from  apple  peelings,  prussic  acid  from  apricot  pits,  alcohol 
from  waste  products  such  as  worthless  potatoes  and  fruit 
pulp,  marmalade  from  cull  oranges,  citric  acid  and  lemon 
flavoring  extract  from  cull  lemons,  sirup,  oil,  extract  of 
tannin,  and  raisin-seed  meal  from  raisins,  and  many  other 
by-products.  A  few  years  ago  these  would  have  been  dis- 
carded as  worthless,  yet  now  their  value  runs  into  millions 
of  dollars  annually.  The  instructive  and  interesting  feature, 
however,  is  that  the  present  number  of  horticultural  by- 
products represents  a  beginning  only.  The  annual  losses  are 
still  immense;  each  loss  is  a  challenge  to  the  intelligence  of 
the  trained  horticulturists  of  America,  and  as  time  goes  on 
new  by-products  will  be  constantly  added  to  the  list. 

404.  Vinegar  manufacture. — Apple  cider  contains  a  cer- 
tain amount  of  sugar,  which,  if  unmolested  for  a  brief  time, 
changes  into  alcohol.  This  change  is  brought  about  by  the 
action  of  bacteria  on  the  sugar.  The  alcohol  in  turn  is 
transformed  into  acetic  acid  by  another  set  of  bacteria. 
Although  other  substances  besides  acetic  acid  are  pres- 
ent in  commercial  vinegar,  acid  is  the  essential  in  the  final 
product. 

If  home-made  vinegar  is  examined  closely,  a  scum  will  be 
seen  over  the  top  of  the  mass,  a  dark-colored  substance  which 
is  commonly  known  as  " mother  of  vinegar."  This  mass  is 
nothing  more  nor  less  than  a  collection  of  large  quantities  of 
the  acetic-acid-forming  bacteria ;  and  whenever  a  new  lot  of 
cider  is  to  be  changed  to  vinegar,  the  process  is  hastened  by 
adding  some  of  the  " mother"  to  it. 

Several  species  of  bacteria  have  the  power  of  changing 
alcohol  into  acetic  acid,  all  of  them  differing  slightly  in  regard 
to  conditions  under  which  they  live.  Since  some  of  these 
species  are  better  than  others,  the  makers  of  vinegar  are  at 
present  endeavoring  to  sort  out  the  more  favorable  types  to 


292  HORTICULTURE  FOR  SCHOOLS 

the  end  that  these  may  be  utilized  exclusively  in  vinegar 
production.  The  use  of  these  pure  cultures  will  without 
doubt  result  in  a  superior  product. 

Vinegar  is  commonly  manufactured  by  the  quick  method. 
Vats  are  filled  with  beech-wood  shavings,  over  which  grain 
alcohol  diluted  with  vinegar  is  allowed  to  trickle.  This  in- 
troduces bacteria  throughout  the  shavings.  A  substance 
containing  alcohol,  such  as  hard  cider,  which  is  to  be  trans- 
formed into  vinegar,  is  then  allowed  to  percolate  through 
these  vats.  As  it  does  so,  the  alcohol  is  acted  on  by  the 
bacteria  and  changed  into  vinegar,  which  is  drawn  off  at  the 
bottom  of  the  vats. 

405.  Olive  oil. — The  olive  is  a  fruit  the  poor  grade  of 
which  can  be  used  to  excellent  advantage  in  the  preparation 
of  a  product  of  considerable  commercial  importance.  Olive 
oil  has  been  used  by  man  from  the  time  of  earliest  recorded 
history  and  remains  today  one  of  the  important  commercial 
products. 

The  oil  is  extracted  from  the  pulp  by  a  two-fold  process  of 
crushing  and  pressing.  The  crushing  was  done  formerly  by 
means  of  a  crude  grinder  operated  by  animal  power.  At  the 
present  time,  the  fruit  is  first  partially  dried  and  then 
crushed  by  power-operated  rollers.  The  pulp  is  inclosed  in 
layers  of  stout  cloth  and  placed  on  a  hydraulic  press. 

The  first  oil  which  comes  off  the  press  is  a  high-grade  com- 
mercial product  used  only  for  the  fancy  trade.  As  pressing 
continues,  the  oil  becomes  poorer  in  quality  and  commands  a 
correspondingly  lower  figure  on  the  market.  With  present 
facilities,  a  considerable  part  of  the  oil  still  remains  un- 
extracted  from  the  pulp,  a  circumstance  which  calls  for  an 
intensive  study  of  the  whole  problem.  Since  that  part 
which  is  extracted  has  a  very  considerable  value  in  the 
aggregate,  and  since  by  this  means  the  poorer  grades  of  fruit 
are  utilized,  the  industry  is  one  of  genuine  economic 
significance. 


INCIDENTAL  PRODUCTS  293 


PRESERVATION    BY   DRYING 

The  changes  that  are  produced  in  fruit  after  it  becomes 
ripe  are  of  two  sorts;  the  first  is  chemical,  the  second  bac- 
terial. 

406.  Chemical  changes. — In  all  cells  certain  chemicals 
known  as  enzymes  are  present.    These  act  on  the  substances 
in  the  cells,  producing  changes  in  them.    For  example,  some 
enzymes  in  the  muscles  of  animals  cause  softening  of  these 
muscles  after  death  while  others  break  down  the  tissues  and 
bring  about- a  ripening  of  meat  whereby  it  becomes  tender.1 
Certain  enzymes  in  fruits  attack  the  carbohydrates  or  the 
proteins,  producing  changes  which  destroy  the  value  of  the 
product.    If  the  fruit  is  to  retain  its  natural  flavor,  the  action 
of  these  enzymes  must  be  prevented.    This  can  be  done  either 
by  heating  or  by  drying. 

407.  Bacterial  changes. — It  has  been  seen  that  wherever 
food,  moisture,  and  warmth  are  present,  bacteria  are  sure  to 
abound  unless  they  have  been  previously  killed  or  excluded. 
To  preserve  fruit  from  bacterial  action,  therefore,  it  is  neces- 
sary either  to  remove  the  heat  or  the  moisture.    The  former 
process  is  cold  storage;  the  latter,  drying  or  evaporation. 

408.  The  fruit-drying  industry. — Where  the  climate*  is 
sufficiently  dry  to  remove  the  moisture  quickly,  fruit  is  cured 
by  the  simple  device  of  laying  it  on  trays  out-of-doors.    In 
the  case  of  common  stone-fruits  such  as  peaches  and  apricots, 
the  pits  are  first  removed  and  the  fruit  then  halved  and 
placed  on  trays  in  the  sun.    The  trays  are  left  exposed  to  the 
sun  for  a  period,  then  are  gathered  up,  piled  on  small  cars, 
and  run  into  air-tight  buildings,  called  sulfuring  houses.    Here 
the  partially  dried  fruit  is  subjected  to  the  fumes  of  burning 
sulfur  for  periods  varying  from  two  to  twelve  hours,  about 
one  pound  of  sulfur  being  used  to  a  ton  of  fruit.    This  sulfur- 
ing  process  is  useful  in  two  ways :  It  improves  the  appearance 

1  Marshall's  Microbiology. 


294  HORTICULTURE  FOR  SCHOOLS 

of  the  fruit,  and  it  prevents  the  growth  of  bacteria  and  fungi. 
Fruit  is  not  dried  so  completely  as  to  remove  all  the  moisture ; 
nor  can  it  always  be  kept  in  perfectly  air-tight  containers; 
it  is,  therefore,  always  slightly  moist,  thus  making  possible 
the  development  of  decay-producing  organisms.  Sulfur,  how- 
ever, prevents  the  growth  of  such  structures,  and  is  used 
wherever  fruit  is  preserved  by  drying. 

409.  The  chemistry  of  sulfuring. — When  sulfur  burns  in 
air,  it  unites  with  oxygen,  forming  a  new  substance  known  as 
sulfur  dioxide.     This  has  the  peculiarly  pungent  odor  so 
characteristic  of  burning  sulfur.     Sulfur  dioxide  gradually 
comes  in  contact  with  the  moisture  of  the  fruit,  forming 
sulfurous  acid,  which,  on  being  exposed  to  the  air,  unites 
with  oxygen  forming  sulfuric  acid.    All  sulfured  dried  fruit, 
therefore,  contains  a  certain  amount  of  sulfuric  acid  and  a 
lesser  amount  of  sulfurous  acid.    When  the  pure  food  and 
drug  act  was  passed  in  1906,  the  chemists  in  charge  of  its 
enforcement  feared  that  these  acids  in  the  fruit  rendered  it 
injurious  to  the  consumer.    Fruit-growers  immediately  real- 
ized that,  if  sulfuring  were  not  allowed,  their  industry  would 
be  destroyed ;  for  sulfuring  not  only  improved  the  appearance 
of  the  fruit,  giving  it  an  amber-like  color  when  dried,  but  also 
prevented  the  growth  of  bacteria  and  fungi  and  kept  away 
injurious  insects,  which  would  otherwise  destroy  large  quan- 
tities.   The  matter  was  submitted  to  a  board  of  experts  and 
after  careful  investigation  it  was  found  that  the  acids  present 
in  moderate  quantities  were  not  injurious.    The  Government 
has,  therefore,  permitted  the  treatment  of  all  dried  fruits 
with  moderate  quantities  of  sulfur  dioxide  gas. 

410.  Drying  of  other  fruits. — The  drying  of  prunes  and 
raisins  differs  from  that  of  other  fruits,  as  they  contain 
sufficient  sugar  to  permit  of  being  dried  without  the  removal 
of  the  pit  or  seeds.    In  the  case  of  prunes,  it  is  necessary  first 
to  crack  the  skins  so  that  the  water  can  escape  rapidly.    This 
is  done  by  dipping  the  prunes  for  a  few  minutes  in  a  solution 


Plate  VIII. — Twig  of  Spiraa  Vanhouttei  in  blossom. 


INCIDENTAL  PRODUCTS  295 

of  lye  made  by  dissolving  one  pound  of  concentrated  lye  in  ten 
gallons  of  water.  They  are  then  rinsed  in  clear  water.  Grapes 
for  raisins  are  cured  in  much  the  same  way.  Sometimes  they 
are  previously  dipped  in  lye,  but  usually  not.  The  seeds  are 
removed  by  special  machinery.  The  work  of  removing  raisins 
from  the  stems,  packing,  and  so  forth,  is  also  performed  in 
the  main  by  machines. 

411.  Effect  of  drying  on  the  industry. — The  process  of 
drying  is  a  great  stabilizer  for  the  fruit  industry.  By  far  the 
greater  part  of  the  fruit  is  sold  to  the  canneries  or  to  the 
fresh  fruit  markets.  If,  however,  prices  are  extremely  low, 
the  grower  may  hold  his  fruit  by  drying,  and  market  it  at  such 
future  time  as  he  sees  fit.  This  prevents  a  glut  on  an  already 
overstocked  market.  On  the  other  hand,  the  canneries  and 
fresh  fruit  trade  use  only  the  choice  product.  The  small- 
sized  fruits  which  are  in  all  respects  as  wholesome  as  the  larger, 
but  which  are  unsuited  for  canning  or  immediate  sale,  may 
then  be  prevented  from  going  to  waste  by  the  drying  process. 

In  those  sections  of  the  country  in  which  the  climate  does 
not  permit  of  drying,  much  attention  is  being  given  to  the  con- 
struction of  special  buildings  known  as  evaporators.  In  these 
buildings  large  quantities  of  fruits  are  dried  by  the  use  of 
artificial  heat,  and  much  which  otherwise  would  be  wasted  is 
thus  saved  for  human  use.  The  drying  of  fruit  in  evapo- 
rators is  independent  of  weather  conditions,  requires  fewer 
trays  to  the  ton  of  dried  product  than  when  the  fruit  is  dried 
out-of-doors,  produces  a  cleaner  product  than  is  obtained  out 
in  the  open  where  more  or  less  dust  and  dirt  sticks  to  the 
fruit,  and  makes  it  easy  to  secure  a  uniformly  dried  product. 
For  these  reasons,  the  evaporator  method  of  drying  is  sure  to 
become  increasingly  popular,  even  in  regions  now  producing 
exclusively  sun-dried  fruits. 


296  HORTICULTURE  FOR  SCHOOLS 


EXERCISES 

EXERCISE  I. — Fruit  drying. 

Materials. — Fruits  suitable  for  drying,  such  as  apples,  pears,  peaches, 
apricots,  prunes,  grapes,  figs;  trays  and  other  utensils  necessary  for 
drying  fruits. 

Procedure. — (1)  Pack,  cut,  and  dry  the  fruit  according  to  the  methods 
discussed  in  the  text.  Record  the  weight  of  the  fruit  before  and  after 
drying.  Obtain  the  market  quotations  for  the  fresh  fruit.  On  the 
basis  of  the  value  of  100  pounds  of  fresh  fruit,  compute  the  price  a 
pound  of  the  dried  product  which  would  have  to  be  realized  in  order 
to  make  drying  profitable.  (2)  If  you  can  obtain  them,  dip  and  dry 
some  prunes.  (3)  Secure  some  fresh  raisin  grapes  and  dry  them. 
(4)  Compare  your  dried  specimens  with  some  obtained  from  the  market. 

EXERCISE  II. — Study  of  dried  fruits. 

Materials. — Samples  of  dried  fruit. 

Procedure. — Examine  as  many  samples  of  dried  fruit  as  possible. 
Notice  special  packs,  and  the  like.  Note  differences  in  sample.  Com- 
pare them  as  to  size,  appearance,  quality. 

EXERCISE  III. — Study  of  by-products. 

Materials. — By-products  from  the  fruit  industry. 

Procedure. — Bring  to  class  samples  of  as  many  kinds  of  horticultural 
by-products  as  you  can  obtain.  Be  prepared  to  explain  how  each  is 
made.  The  samples  brought  by  the  whole  class  should  make  a  varied 
and  interesting  collection. 

EXERCISE  IV. — Making  by-products.  It  is  suggested  that  the  class 
make  one  kind  of  horticultural  by-product,  such,  for  example,  as 
vinegar,  or  olive  oil.  The  choice  of  by-product  will  be  determined  by 
the  locality. 


CHAPTER  XXI 
THE  USE  OF  ORNAMENTAL  PLANTS 

LANDSCAPE-GARDENING  is  the  art  of  so  arranging  trees, 
shrubs,  lawns,  and  other  features  of  a  landscape  as  to  produce 
an  effect  pleasing  to  the  eye.  In  its  more  pretentious  sense, 
it  signifies  the  laying  out  of  large  tracts  of  land,  including 
sometimes  hundreds  or  even  thousands  of  acres,  as  parks  and 
private  estates;  but  the  term  is  also  applied  to  the  ornamen- 
tation of  home  and  school  grounds  occupying  even  so  small 
an  amount  of  space  as  a  portion  of  a  city  lot.  The  element 
of  artistic  design  and  subdivision  of  grounds  enters  largely 
into  the  practice  of  the  landscape  art. 

There  are  several  reasons  why  every  student  of  horticulture 
should  have  at  least  a  slight  knowledge  of  the  practices  and 
materials  employed  in  the  processes  of  landscape-gardening: 

1.  He  should  be  able  to  plan  ornamental  plantings  for  his 
own  home  grounds,  for  such  features  have  both  an  aesthetic 
and  economic  value. 

2.  He  should  know  something  of  the  concepts  governing 
such  plantings,  whether  the  space  be  small  or  large,  in  order 
that  he  may  appreciate  what  others  have  done. 

3.  He  should  know  the  common  ornamental  material  of 
his  locality,  for  the  mere  ability  to  name  the  plant  will  of 
itself  give  him  a  perpetual  interest  in  it,  and  also  lead  him 
to  a  knowledge  of  its  adaptabilities. 

A  complete  understanding  of  landscape-gardening  calls  for 
many  years  of  close  study;  for  there  are  technical  details 
that  are  exceedingly  complex  and  difficult.  It  is  possible, 
however,  to  state  some  of  the  fundamental  considerations  in 

297 


298  HORTICULTURE  FOR  SCHOOLS 

the  brief  space  of  a  chapter;  and  if  the  novice  studies  and 
observes  these  elements,  he  will  not  go  far  astray  in  the  work 
he  may  undertake,  although  he  may  not  make  an  artist  of 
himself. 

412.  The  plan. — No  work  should  be  undertaken  until 
every  detail  has  been  worked  out  and  set  down  on  paper. 
If  the  buildings  have  not  yet  been  constructed,  their  proposed 
position  should  be  indicated.    All  features  of  a  permanent 
character  should  be  included.    There  must  be  a  drawing  to 
a  scale  sufficiently  large  to  show  the  relative  sizes  of  all  the 
material  to  be  used.     Shrubs,  trees,  lawns,  walks,  drives, 
flower-beds,  and  other  features  will  be  included  in  the  draw- 
ing.   The  shrubs  and  trees  will  be  designated  by  number  and 
the  numbers  and  names  indicated  on  a  separate  sheet.    The 
location  of  each  shrub  and  tree  is  shown  by  a  small  half  circle. 

413.  The  lawn. — The  heart  and  center  of  the  usual  land- 
scape is  the  lawn  or  an  open  space.    This  was  learned  from 
nature,  and  has  been  utilized  for  so  many  years  that  its  im- 
portance has   now  come  to  be  very  generally  recognized. 
Every  care  must  be  exercised,  therefore,  to  have  the  lawn 
fine  and  as  free  from  defects  of  every  sort  as  possible. 

414.  Shrubbery. — The  finest  effects  are  secured  when  one 
approximates  most  closely  nature's  ways.    In  nature  shrubs 
are  almost  invariably  in  masses;  only  rarely  do  they  occur 
as  isolated  specimens.    When  shrubs  are  set,  therefore,  they 
should  be  grouped,  putting  enough  plants  together  so  that 
the  effect  will  be  of  a  mass,  not  a  collection  of  individuals. 
Occasionally  a  single  shrub  may  be  placed  by  itself;  but  this 
will  be  the  exception  rather  than  the  rule,  and  will  be  dictated 
only  by  exceptional  circumstances. 

Different  kinds  of  shrubs  may  be  blended  together  in  the 
same  shrubbery  group,  thus  avoiding  a  dull  uniformity;  but 
care  must  be  taken  that  the  shrubs  are  of  such  nature  that 
they  will  harmonize.  A  willow,  for  example,  would  not  look 
well  with  a  cactus,  even  though  each  might  be  attractive  by 


THE   USE  OF  ORNAMENTAL  PLANTS  299 

itself.  The  foliage  and  habit  of  growth  of  the  different  mem- 
bers of  a  group  should  also  be  in  harmony,  and  if  the  shrubs 
bear  flowers  which  are  at  all  conspicuous,  conflicting  colors 
should  not  be  placed  together.  Shrubs  should  also  be  graded 
as  to  size,  the  higher  in  the  background,  the  lower  about  the 
outer  edge.  In  some  cases,  however,  the  best  effects  are 
produced  by  bold  lines  or  masses  of  one  species  of  plant. 

415.  Shrub  planting. — When  shrubs  are  set  out,  they 
should  not  be  placed  too  close  together,  lest  the  effect  be  so 
compact  as  to  appear  artificial;  room  also  must  be  left  for 
convenience  in  irrigation  and  cultivation.    At  the  same  time, 
the  distances  between  them  must  not  be  very  great.    There 
is  a  happy  mean  which  differs  for  the  various  shrubs,  local- 
ities, and  soils,  and  which  must  be  learned  by  experience.    In 
general  it  may  be  said  that  shrubs  set  two  to  four  feet  apart 
grow  quickly  into  a  single  group;   if  they  seem  to  be  too 
close  together  as  they  grow  older,  a  part  may  be  removed. 

Usually  the  individual  plants  should  be  set  in  such  a  way 
as  to  avoid  any  suggestion  of  straight  lines.  In  orchards  the 
trees  are  desired  in  rows,  but  ornamental  gardens  are  more 
pleasing  when  the  planting  does  not  suggest  artificial 
arrangement. 

416.  Trees. — From   the   standpoint   of   the   landscape- 
gardener,  there  are  two  kinds  of  trees,  those  with  round  tops 
like  the  oak  and  elm,  and  those  with  pointed  tops  like  the 
pine  and  fir.    The  trees  with  round  tops  are,  of  course,  to  be 
preferred  where  shade  is  desired;    in  general,  the  pointed- 
topped  trees  excel  in  beauty  and  symmetry  of  form. 

Each  tree  must  be  studied  for  what  it  connotes  or  suggests. 
The  oak,  for  example,  possesses  an  atmosphere  of  strength 
and  repose.  The  palm  suggests  the  oasis  of  the  desert.  The 
Italian  cypress  is  more  or  less  formal  in  appearance,  and 
should  be  used  only  where  the  treatment  calls  for  such 
formality.  Whenever  trees  or  shrubs  possess  singular  beauty 
or  charm  as  specimen  plants,  they  should  be  set  by  them- 


300  HORTICULTURE  FOR  SCHOOLS 

selves,  apart  from  the  groups ;  and  their  beauty  may  be  still 
further  emphasized  by  planting  groups  of  trees  or  shrubs  to 
serve  as  a  background. 

417.  Buildings. — The  architecture  of  the  building  will 
determine  largely  the  nature  of  the  plantings  to  be  used 
about  it.     A  rich  formal  style  of  architecture  will  demand 
plants  of  similar  nature:   columnar  trees,  like  the  Irish  yew 
and  Italian  cypress;  compact  shrubs,  like  clipped  specimens 
of  English  laurel.    The  less  pretentious  buildings  will  call  for 
less  formal  treatment.    Almost  without  exception,  the  base 
of  the  building  should  be  hidden  by  shrubbery.    The  entrance 
may  be  emphasized  by  higher-growing  clumps  of  similar 
material;   the  corners  may  be  screened  by  upright  growing 
shrubs  or  small  trees.    The  shrubbery  should  be  planted  in 
irregular  lines,  groups  of  higher  growing  specimens  appearing 
here  and  there. 

418.  Walks  and  drives  should,  wherever  possible,  be  laid 
out  in  curves  rather  than  straight  lines,  as  they  are  less  con- 
spicuous and  lead  restfully  from  point  to  point  by  unnoticed 
gradations.    Further,  if  the  plantings  have  been  judiciously 
placed,  there  is  in  the  plan  the  element  of  surprise,  as  a  turn 
here  or  an  opening  there  reveals  some  vista  not  perceived 
before.    If  the  curve  of  the  walk  is  unduly  sharp,  there  must 
be  clumps  of  shrubbery  on  the  concave  side. 

However,  the  basic  fact  that  a  straight  line  is  the  shortest 
distance  between  two  points  should  never  be  lost  sight  of  in 
walk  construction;  and  the  curves  should  never  give  the 
appearance  of  being  forced  or  abnormal  or  located  in  the 
wrong  place.  From  the  standpoint  of  the  landscape,  the 
effect  would  be  more  beautiful  if  walks  and  drives  were  dis- 
pensed with  altogether;  but  since  this  is  quite  out  of  the 
question,  they  must  be  as  beautiful  and  restful  as  possible, 
without  ever  forgetting  the  element  of  convenience. 

419.  Straight  lines. — It  has  already  been  stated  that 
straight  lines  should  be  avoided  wherever  possible.    At  the 


THE   USE  OF  ORNAMENTAL  PLANTS  301 

same  time,  there  are  circumstances  that  call  for  the  contrary 
treatment.  For  example,  the  trees  planted  in  parkings  as 
borders  to  streets  or  avenues  should  be  arranged  in  rows 
parallel  to  the  walks  or  drives  to  which  they  are  adjacent. 
The  general  rule  is  this:  When  the  artificial  feature,  such  as 
the  walk,  or  avenue,  is  the  dominant  note  of  the  landscape, 
the  plantings  must  conform  to  it.  It  is  to  be  remembered, 
however,  that  the  skilful  gardener  makes  the  walk  or  drive 
subordinate  wherever  possible,  and  arranges  his  plant  material 
accordingly  in  a  natural  way. 

PLANT  MATERIALS 

One  of  the  first  questions  that  will  arise  will  be:  What 
should  be  planted  here?  And  this  immediately  calls  up  the 
entire  problem  of  plant  material.  There  are  at  present  many 
thousands  of  plants  under  cultivation.  It  would,  of  course, 
be  difficult  for  any  one  person  to  know  all  or  even  most  of 
them ;  and  also  the  greater  number  are  adapted  to  particular 
localities  or  situations  only.  For  all  practical  purposes  it 
suffices,  therefore,  if  the  plants  that  have  proven  most  useful 
in  the  student's  own  locality  be  studied  and  their  names  and 
characteristics  learned. 

In  studying  these  plants,  one  should  not  think  that  a  book 
is  absolutely  necessary.  Some  such  work  as  Bailey's  Standard 
Cyclopedia  of  Horticulture  is  of  course  useful ;  but  the  student 
should  learn  also  to  study  the  plant  itself,  noting  the  general 
characteristics:  height,  color  of  foliage  and  flower,  habit  of 
growth.  He  should  study  the  leaves,  flowers,  branches,  all 
parts  of  the  plant,  and  should  become  so  familiar  with  it  that 
he  can  name  it  wherever  seen.  Then  he  should  think  of  it  in 
connection  with  the  landscape — what  plant  it  harmonizes 
with,  what  situation  it  is  best  adapted  to.  The  process  is 
slow  and  laborious,  but  very  much  worth  while. 

It  may  be  in  order  here  to  mention  briefly  a  few  desirable 


302  HORTICULTURE  FOR  SCHOOLS 

plants  for  landscape-gardening,  not  to  suggest  specific  plants, 
but  merely  to  call  attention  to  some  of  the  material  available 
in  practically  all  parts  of  North  America. 

420.  Climbing  vines. — No  single  feature  of  landscape- 
gardening  can  add  more  to  the  attractiveness  of  the  average 
home  than  a  judicious  use  of  climbing  plants.    They  cover 
the  harsh  outlines  of  buildings,  or  screen  porches  and  windows 
from  the  glare  of  the  midsummer  sun.    The  foliage,  by  its 
constant  evaporation  of  moisture,  assists  in  keeping  down  the 
temperature,  and  supplies  the  fresh  green  so  beautiful  to 
the  eye. 

As  a  rule,  climbers  are  easy  to  start,  and  require  little  care 
once  they  are  well  established.  There  are  both  evergreen 
and  deciduous  forms,  so  if  the  buildings  are  too  damp  or 
dark  in  the  winter,  the  deciduous  kinds  may  be  used.  Some 
cling  by  vacuum  cups  or  muscilaginous  excretions,  others 
fasten  themselves  to  objects  by  tendrils  or  by  twining  about 
them,  while  still  others  have  to  be  supported  on  trellis  work. 
Here  again  there  is  ample  latitude  for  choice. 

421.  Boston  ivy. — One  of  the  best  climbers  is  the  Boston 
ivy.    The  technical  name  is  Parthenocissus  tricuspidata;  in 
parts  of  the  country  it  is  sold  under  the  name  of  Ampelopsis 
Veitchii.    It  is  deciduous,  although  there  is  now  an  evergreen 
form  on  the  market.    The  plant  is  a  member  of  the  grape 
family.     The  leaves  resemble  somewhat  those  of  the  wild 
grape,  and  the  little  clusters  of  small  berry-like  fruits  suggest 
strongly  miniature  bunches  of  grapes. 

Boston  ivy  grows  to  a  great  height,  clinging  to  walls  by 
means  of  tendrils  which  secrete  a  mucilaginous  substance. 
It  has  a  wealth  of  glossy  green  foliage  which  persists  during 
the  greater  part  of  the  year. 

422.  Virginia    creeper,    Parthenocissus    quinquefolia,    is 
closely  related  to  the  Boston  ivy.     (Quinque  means  five ;  and 
the  name  is  derived  from  the  fact  that  the  leaves  are  com- 
pound, having  five  leaflets.)     This  plant  does  not  cling  so 


THE   USE  OF  ORNAMENTAL  PLANTS  303 

tenaciously  as  does  the  Boston  ivy;  but  it  makes  a  heavy 
growth  of  foliage,  and  is  frequently  used  as  screening  for 
porches  or  in  situations  requiring  a  heavy  mass  of  greenery. 

423.  Wisteria  is  another  climber  that  finds  great  favor  in 
all  parts  of  the  world.    It  is  a  member  of  the  pea  family,  as 
can  readily  be  seen  by  the  pea-shaped  flowers.    The  flowers 
are  borne  in  clusters  which  in  many  cases  are  over  a  foot  in 
length  and  of  strikingly  beautiful  appearance.     The  leaves 
are  compound  and  resemble  those  of  many  other  members  of 
this  family.    The  plant  is  a  great  favorite  in  Japan  where  it 
is  used  very  extensively  and  where  its  cultivation  has  been 
brought  to  a  high  state  of  excellence.     The  Japanese  give 
especial  attention  to  the  pruning  for  flowers.    They  are  so 
successful  in  this  respect  that  the  flower  clusters  are  sometimes 
two  or  three  feet  in  length. 

The  rigid  stems  of  the  plant  may  be  trained  over  pergolas 
with  especially  fine  effect ;  and  this  is  often  done.  Sometimes 
the  stems  are  pruned  back  and  the  plant  assumes  the  habit  of 
a  shrub.  When  this  is  the  case,  the  wisteria  presents  a  striking 
appearance  with  its  many  clusters  of  purplish  flowers.1 

424.  Shrubs. — Such  a  variety  of  shrubs  is  available  for 
planting  and  the  different  situations  in  the  landscape  are  so 
exacting  in  their  individual  requirements  that  it  is  difficult 
to  suggest  a  few  shrubs  which  would  serve  all  purposes. 

425.  Bridal  wreath  is  one  of  the  commonest  of  all  shrubs 
and  is  found  in  widely  separated  sections  of  the  United  States. 
The  technical  name  is  Spircea  Vanhouttei.    It  is  a  member  of 
the  rose  family  and  is  grown  primarily  for  its  fine  mass  of 
white  blossoms  which  cover  the  plant  in  dense  clusters  in  the 
early  spring.    (Plate  VIII.)    The  shrub  is  deciduous,  but  in 
the  warmer  parts  of  the  United  States  retains  some  of  its 
foliage  during  the  winter.    It  is  not  high-growing,  attaining 
a  maximum  height  of  five  to  six  feet.    It  makes  an  ex- 

1  There  are  other  colors  besides  the  purple,  among  them  white,  pink,  and 
blue. 


304  HORTICULTURE  FOR  SCHOOLS 

cellent  shrub  for  massed  plantings  about  the  bases  of  build- 
ings or  as  a  border  for  lawns  or  in  similar  situations. 

426.  Viburnum. — One  of  the  best  known  members  of  this 
genus  is  Viburnum  Opulus,  commonly  called  snowball.   The 
flowers  are  borne  in  dense  spherical  clusters  and  make  a  very 
showy  appearance. 

Another  ornamental  species  is  Viburnum  Tinus,  the  com- 
mon name  of  which  is  Laurestinus.  This  is  frequently  kept 
closely  clipped  and  used  as  a  hedge  plant,  but  may  be  allowed 
to  grow  to  its  full  height.  It  attains  a  maximum  height  of 
twelve  or  fifteen  feet.  Viburnum  is  a  member  of  the  same 
family  as  the  honeysuckle  and  the  leaves  strongly  resemble 
those  of  the  latter,  although  the  habit  of  growth  of  the  two  is 
entirely  different.  The  viburnum  is  easily  propagated  from 
seed  and,  since  it  is  grown  with  very  little  care,  it  is  very  com- 
monly used  as  an  ornamental  plant. 

427.  Barberry.1 — A  number  of   species  of  barberry  are 
used  as  ornamental  plants  in  North  America.    The  technical 
name  is  Berberis.    One  of  the  species,  Berberis  Thunbergii, 
is  a  low  dense  shrub  with  brilliant  foliage  and  bright  berries; 
it  is  an  excellent  ornamental  where  low-growing  material  is 
desired.    One  of  the  points  especially  in  its  favor  is  that  it  is 
fairly  tolerant  of  shade,  although  -it  grows  also  very  well  in 
bright  sunlight.     A  closely  related  form,  sometimes  called 
Berberis  Aquifolium  but  usually  classed  as  a  separate  genus 
under  the  name  Mahonia  Aquifolium,  is  the  state  flower  of 
Oregon.    This  plant  is  also  rather  tolerant  of  shade  and  is 
characterized   by   glossy   bronze-green   foliage   and   yellow 
flowers.     It  is  a  very  handsome  shrub  growing  somewhat 
higher  than  Berberis  Thunbergii. 

428.  Philadelphus. — Among  the  higher-growing  shrubs, 
one  of  the  most  popular  is  mock  orange  or  syringa.    There  are 

1  In  wheat-growing  areas  of  the  United  States,  it  must  be  remembered  that 
the  barberry  is  an  intermediary  host  for  the  common  wheat  rust  and  its  use 
as  an  ornamental  plant  should,  therefore,  be  avoided. 


THE   USE  OF  ORNAMENTAL  PLANTS  305 

several  species,  the  more  common  being  probably  Philadelphia 
coronarius.  The  shrub  is  deciduous  and  the  species  mentioned 
above  grows  to  a  height  of  eight  to  twelve  feet.  The  flowers 
are  white  with  yellow  centers  and,  while  they  resemble  in  a 
general  way  the  flowers  of  the  orange  (hence  the  name  mock 
orange),  they  are  much  larger  and  more  showy. 

The  members  of  this  genus  are  found  in  widely  separated 
parts  of  the  world;  some  of  the  forms  come  from  China,  some 
from  the  Himalayas,  others  from  Mexico  and  still  others  are 
wild  in  the  United  States. 

429 .  Hydrangea  is  essentially  a  shade-loving  plant .    There 
are  many  different  forms,  most  of  them  shrubs,  but  a  few  are 
climbing  vines.    They  are  deciduous  and  are  characterized 
by  rather  large  leaves  and  flowers  borne  in  dense  heads  or 
clusters.    These  flowers  are  commonly  pink  in  color  but  they 
can  be  changed  from  pink  to  blue  by  the  addition  of  iron  or 
lampblack  to  the  soil.    The  hydrangea  is  propagated  readily 
from  cuttings  and  grows  rapidly  but  require.8  a  fairly  moist 
and  rich  soil  for  best  development.    Most  of  the  ornamental 
forms  should  be  pruned  rather  heavily  every  winter  and  some 
of  them  are  rather  susceptible  to  frost.    The  species  should, 
therefore,  be  selected  with  some  care,  keeping  in  mind  the 
experience  of  the  individual  community. 

430.  Trees. — So  many  trees  are  suitable  for  landscape- 
gardening  purposes  that  it  is  out  of  the  question  even  to 
attempt  to  suggest  a  few  as  being  preferable  to  others.    The 
oak  is  found  in  all  the  parts  of  the  United  States.    There  are 
both  deciduous  and  evergreen  species  and  the  plants  differ  in 
size  from  small  shrubs  to  very  large  trees.     A  number  of 
plants  bear  the  name  of  oak  which  in  a  botanical  sense  have 
no  relationship  whatever.    Poison  oak,  for  example,  belongs 
to  an  entirely  different  group  of  plants,  and  Australian  silk 
oak,  technically  known  as  Grevillea  robusta,  does  not  even 
resemble  the  oak  with  respect  to  flower,  leaf,  or  habit  of  tree. 

There  are  several  kinds  of  elm,  some  of  them  native  to 


306  HORTICULTURE  FOR  SCHOOLS 

North  America.  This  is  one  of  the  grandest  trees  and  is 
extensively  used  in  ornamental  planting.  The  maple,  known 
technically  as  Acer,  has  several  species  native  to  North 
America  and,  like  the  elm,  is  magnificent  for  ornamental 
purposes.  There  are  also  a  large  number  of  coniferous  trees : 
spruce,  hemlock,  fir,  cypress,  and  others,  some  of  them  native 
to  North  America  and  some  imported  from  other  countries. 
In  general,  the  landscape-gardener  will  attain  good  results  by 
using  plants  native  to  the  locality  where  he  is  working,  but 
this  should  not  prevent  his  drawing  on  the  rich  abundance  of 
material  which  is  available  from  foreign  lands. 

431.  Lawn  grasses. — The  most  important  single  factor  of 
the  landscape  is  the  lawn  or  open  space.  It  is  the  center 
about  which  the  whole  plan  is  drawn .  If  properly  prepared ,  no 
feature  of  the  landscape  is  more  beautiful,  but  if  neglected,  it 
will  show  defect  very  quickly.  The  first  thought  of  the  land- 
scape-gardener should,  therefore,  be  to  have  the  ground  in 
the  best  possible  condition  as  regards  both  texture  and  rich- 
ness of  the  soil,  as  well  as  evenness  of  surface. 

A  large  number  of  different  grasses  are  available  for  lawn- 
planting  and  the  choice  will  depend  to  a  considerable  extent 
on  the  experience  of  the  community.  Kentucky  blue-grass 
alone  or  in  combination  with  white  clover  is  used  with  success 
in  many  sections  of  North  America.  In  some  parts  of  the 
South,  Bermuda-grass  is  practically  the  only  material  which 
can  be  employed  since  it  grows  so  readily  as  to  displace  any 
other  plant.  The  objection  to  Bermuda-grass  is  its  appear- 
ance in  the  winter,  as  the  leaves  turn  light  brown,  and  the 
lawn  appears  dead  during  a  considerable  portion  of  the  year. 

Another  plant  sometimes  used,  especially  in  the  warmer 
parts  of  California,  is  Lippia  canescens.  This  thrives  under 
circumstances  so  unfavorable  that  no  other  material  could 
live.  It  endures  a  great  amount  of  drought  and  persists  each 
year  even  when  subject  to  much  tramping.  On  that  account 
it  is  commonly  used  in  school-yards.  The  plant  is  a  trailer, 


THE  USE  OF  ORNAMENTAL  PLANTS  307 

forming  a  dense  mat  on  the  ground  and  is  characterized  by 
gray-green  leaves  and  small  purplish- white  flowers.  It  does 
not  require  mowing  unless  it  is  desired  to  keep  the  flowers 
removed.  A  lawn  of  this  material  never  has  the  beautiful 
appearance  of  well  kept  Kentucky  blue-grass. 

One  interesting  point  regarding  Lippia  canescens  is  that 
it  is  established  in  the  first  place  from  cuttings,  as  very  few 
seeds  are  produced.  These  cuttings  are  put  in  the  ground  a 
few  inches  or  even  a  foot  apart,  and  spread  quickly  until  they 
form  a  carpet. 

432.  Ground  cover. — Frequently  it  is  desired  to  have  the 
space  under  trees  and  shrubbery  covered  with  a  solid  mass  of 
green  material.     A  number  of  plants  can  be  used  for  this 
purpose ;  the  requirements  are  that  they  grow  fairly  rapidly 
in  the  shade  and  form  a  mat  of  foliage.    The  two  most  com- 
monly used  for  this  purpose  are  English  ivy  and  Vinca  minor 
or  periwinkle.    Both  of  these  are  evergreens  which  thrive  in 
moist  shady  situations. 

THE  LANDSCAPE  PLAN 

With  the  material  the  landscape-gardener  has  at  his  dis- 
posal, he  can  produce  widely  varying  effects.  The  type  of 
plants  which  he  uses  and  the  way  he  groups  them  gives  to 
the  landscape  that  particular  quality  which  is  known  as 
"style." 

433.  Formal  style. — There  has  always  been  a  tendency, 
happily  much  more  common  formerly  than  now,  to  arrange 
grounds  after  the  manner  of  definite  geometrical  designs,  as 
though  a  garden  were  an  illustration  of  a  Euclidian  proposi- 
tion.    In  this  style  of  landscape-gardening,  all  lines  are 
perfectly  straight,  or  assume  the  forms  of  circles,  five-pointed 
stars  or  triangles,  or  other  regular  figures.    The  hedges  are 
kept  closely  clipped,  the  shrubs  are  trimmed  into  odd  and 
sometimes  grotesque  shapes.    Flowers  and  other  ornamental 
plants  may  be  used,  but  the  vegetation  is  invariably  sub- 


308  HORTICULTURE  FOR  SCHOOLS 

ordinated  to  the  design.  Some  of  the  most  famous  gardens 
of  the  Old  World  and  of  early  colonial  days1  were  of  this  sort  • 
and  many  have  tried  to  copy  the  idea  in  a  small  way  on  their 
home  grounds. 

The  result  needs  no  description,  for  it  can  be  observed  at 
first  hand  in  almost  every  town  and  village  of  the  country. 
Grounds  laid  out  in  this  way  demand  constant  care,  and 
when  neglected  they  very  soon  have  a  run-down  appearance. 
There  is  a  field,  sometimes,  for  formal  gardening  of  this  sort, 
but  not  for  the  average  American  home  grounds. 

434.  The  natural  style. — In  direct  contrast  to  the  highly 
artificial  effect  of  the  formal  gardens  are  the  graceful  un- 
consciously beautiful  lines  of  the  natural  style.  This  type 
takes  its  inspiration  from  the  out-of-doors,  from  the  moun- 
tains and  woods,  and  meadows;  from  the  landscape-gardening 
of  nature  itself. 

"  In  this  connection,"  says  John  McLaren,2  "  it  is  suggested 
that  some  consideration  be  given  to  what  may  be  termed  the 
happy  accidents  of  nature's  plantings,  for  in  some  of  the  un- 
touched virgin  spots  in  nature's  garden  there  are  scenes  more 
soft  and  more  beautiful  than  anything  our  gardening  has  yet 
produced.  Those  who  have  undertaken  to  do  what  we  are 
now  considering,  that  is,  to  plant  a  pleasure  garden  and  lawns, 
and  are  in  doubt  as  to  how  to  establish  the  lines  of  the  lawns 
or  groups  of  trees,  shrubs  and  flowers,  may  get  invaluable 
suggestions  as  to  how  to  arrange  them  in  harmonious  com- 
position if  they  will  do  as  our  best  painters  do — namely,  go 
into  the  natural  forests  of  our  hills  and  hillsides,  or  the 
meadows  and  baughs  of  our  valleys,  and  select,  from  the 
innumerable  beautiful  scenes,  the  one  whose  beauty  most 
appeals  to  them  and  which  seems  to  best  fit  the  general  out- 
line of  the  site  for  which  the  plans  are  being  prepared.  Then 
let  the  measurements  of  this  part  of  nature's  garden  be  care- 

1  See  Standard  Cyclopedia  of  Horticulture,  Vol.  Ill,  plate  XL VI. 

2  Gardening  in  California,  Landscape  and  Flower. 


THE   USE  OF  ORNAMENTAL  PLANTS  309 

fully  taken,  figuring  what  are  its  length,  and  its  breadth; 
what  are  the  depth  and  width  of  the  grassy  bays  which  seem 
to  meander  through  the  forest ;  also  the  form  and  shape  which 
these  bays  assume.  It  will  be  found  that  nature  seldom  runs 
straight  lines  and  shaped  curves.  Let  the  woody  promon- 
tories be  measured,  figuring  how  far  each  one  projects  into  the 
meadow  and  noting  how  nature  has  done  its  planting — how 
far  one  tree  is  from  the  other,  and  how  harmonious  the  whole 
plan  is. 

"After  having  sketched  into  a  map  all  of  the  trees  with 
their  names  and  characteristics,  the  different  shrub-growths 
should  next  be  similarly  studied  and  sketched  in,  especially 
noting  how  they  are  distributed.  After  these,  and  any  other 
data  which  seem  to  be  of  importance  in  the  general  effect,  are 
carefully  platted,  let  this  rough  sketch  be  laid  out  to  scale 
and  reduced  or  enlarged  to  fit  the  plan  for  the  proposed 
grounds.  If  the  propositions  of  the  original  are  faithfully 
carried  out  and  initiated  in  the  form  and  outlines  of  the 
lawns  and  in  the  character  and  planting  of  the  trees  and  un- 
dergrowths,  the  result  will  be  a  delight  to  the  owner,  and  an 
artistically  laid  out  property." 

EXERCISES 

EXERCISE  I. — Plant  materials. 

Materials.— Secure  specimen  plants  of  Spiraea,  Mahonia,  Hydrangea, 
Parthenocissus,  Wisteria,  Viburnum,  Philadelphus,  or  any  other  orna- 
mental shrubs  and  climbing  vines  ef  the  locality. 

Procedure. — Make  drawings  of  leaves  and  if  possible  of  flowers  of 
each  of  the  shrubs  and  vines  obtained  for  study.  In  connection  with 
these  drawings,  make  permanent  notes  featuring  the  following  points: 
Size  of  shrub  when  mature,  kind  of  wood  used  for  cuttings,  special 
points  on  propagation,  situations  to  which  the  plant  in  question  is 
adapted,  general  appearance  and  desirability  for  landscape-gardening 
purposes.1 

iTo  the  Instructor:  This  exercise  may  easily  be  extended  to  cover  a 
dozen  or  more  laboratory  periods,  if  desired,  and  should  include  trees  and 
possibly  flowering  plants  as  well  as  shrubs  and  vines. 


310  HORTICULTURE  FOR  SCHOOLS 

EXERCISE  II. — The  landscape  plan:   A  project. 

Each  student  should  beautify  all  or  a  portion  of  his  own  home 
grounds,  making  a  drawing  to  scale  in  the  class,  indicating  the  shrubs, 
vines,  and  other  material  which  he  plans  to  use.  He  .should  then, 
under  the  direction  of  the  instructor,  put  the  grounds  into  shape  and 
set  out  the  plants. 


INDEX 


Acer,  306 

Acetic  acid,  a  by-product,  290 
Acid  in  oranges  and  lemons  com- 
pared, 204 
Acreage  under  irrigation  in  United 

States,  144 
Acre-foot,  149 

inch,  129 

Adulterated  seed,  49 
Adventitious  bud,  27,  217 

denned,  59 
Advertising  of  citrus  fruits,  exercise, 

205 

Africa  explored  for  wild  plants,  7 
Alcohol,  a  by-product,  291 
Alkali,  152 

indicated  by  certain  plants,  120 
Almond,  191-192 

blossoming  period  of,  192 

diseases  of,  192 

Growers'    Exchange,    California, 
192 

marketing  of,  192 

pollination  of,  192 

propagation  of,  192 

statistics  regarding,  191 
Alternate  bearing,  29 
Ammonium  sulfate,   a  by-product, 

290 

Ampelopsis,  302 

Anemophilous  plants,  denned,  165 
Aniline,  a  by-product,  290 
Annular  budding,  76 
Anther,  illustrated,  158 


Anthracnose,  256 

on  currant  and  gooseberry,  214 
Ants  and  plant-lice,  239 
Aphids,  225 

illustrated,  240 
Apple,  bitter-rot,  illustrated,  257 

diseases  of,  182 

geographical  distribution  of,  181 

insects  injurious  to,  182 

origin  of,  180 

tree    borer,    study    of,    exercise, 
244 

varieties  of  in  America,  181 
Approach-grafting,  81 
Ann  of  grape,  217 
Armored  scale,  control  of,  238 

described,  237 
Artesian  wells,  148 
Artichoke,  Jerusalem,  95 
Ascent  of  water  in  plant,  37 
Asexual  propagation,  69 
Ash,  dissemination  of  seed  of,  44 
Asphalt,  a  by-product,  290 
Auction  market,  280 
Australian  silk-oak,  305 
Avocado,  a  semi-tropical  fruit,  204 

B 
Bacteria    in    vinegar    manufacture, 

291 

Bacterium,  248-249 
Balling    saccharimeter    for    testing 

grapes,  263 
test,  exercise,  273 
Barberry,  304 


311 


312 


HORTICULTURE  FOR  SCHOOLS 


Bark,  formation  of,  26 

-graft,  81 

Bean,  cultivation  of,  110 
description  of,  41 
history  of,  109 

Bearing  habits  of  grape  vine,  218 
Bees  as  pollenizers,  165 
relation  of  pollen  and  nectar  to, 

166 

Beet,  care  of,  93 
climate  for,  92 
fertilizer  for,  93 
soil  adapted  to,  92 
varieties  of,  92 
Beggar-ticks,  dissemination  of  seed 

of,  44 

Begonia  Rex,  propagation  of,  58 
Bellflower  apple,  54 
Bench-grafting,  78 
Benzine,  a  by-product,  290 
Berberis  Aquifolium,  304 

Thunbergii,  304 
Berry,  fruit  of  tomato  and  potato  a, 

5-6 
production,  exercises  dealing  with, 

221-222 
Bitter-rot,  257 

Blackberry,  cultivation  of,  211 
fruit,  where  borne,  210 
history  of,  209 
picking,  packing  and  shipping  of, 

211 

planting  of,  210 
pollination  of,  211 
propagation  of,  59,  210 
varieties  of,  211 
Black  scale,  illustrated,  237 
Blister-mites,  242 
control  of,  243 
Blister-rust,  White  Pine  on  currant 

and  gooseberry,  214 
Blooming  periods,  study  of,  179 
Blue-grass,  Kentucky,  306 
Bordeaux    mixture    for    control    of 

brown-rot,  254 
paste  for  gum  disease,  255 
for  anthracnose,  214 


Borer,  flat-headed,  230 
round-headed,  230 
shot-hole,  231 
Borers,  230 
Boston  ivy,  302 
Box-elder,  dissemination  of  seed  of, 

44     , 

Boxes,  arrangement  of  fruit  in,  266 
Bramble  tribe,  180 
Branch  of  grape,  217 

roots,  manner  of  growth,  21 
Breathing  system  of  insects,  224 
Bridal  wreath,  303 
Bridge-grafting,  82 
British  Columbia,   peach  areas  in, 

184 

plums  grown  in,  187 
Broker,  279 
Brown-rot,  254 
Brussels  sprouts,  104-105 
Bryophyllum,  propagation  of,  58 
Budding,  exercise,  83 
illustrated,  73 
-knife,  73 
limits  of,  69 
operation  of,  72 
uses  of,  69 
Bud-selection,  11 
Buds,  types  of,  27 
Bud-wood,  care  of,  72 

selection  of,  71 

Buildings,    their   relation    to    land- 
scape-gardening olan,  300 
Bulb  crops,  92 
Bulblets,  64 
Bulbs,  64 

Bull,  Ephraim  W.,  215 
Burdock,  dissemination  of  seed  of, 

44 

Bureau  of  Plant  Industry,  7 
Butterfly,  metamorphosis  of,  225 
moth  group  of  insects,  224 
mouth  parts  of,  226 
By-products  company,  285 
defined,  290 
exercise,  296 
in  horticulture,  291 


INDEX 


313 


Cabbage,  geography  of,  103 

history  of,  103 

wild,  illustrated,  103 

worm,  104 
California  Fruit  Growers'  Exchange, 

284 

Callus,  formation  of,  57,  68 
Calyx,  parts  of,  159 
Cambium,  illustrated,  24 
Canada,  production  of  plums  in,  187 
Cane  of  grape,  217 

pruning  of  grape,  219 

wilt,  currant,  214 
Canker,  citrus,  199 

worms,  232 
Caprifig,  203 

Carbolic  acid,  a  by-product,  290 
Carbon  dioxide  used  by  leaf,  32 
Carrot,  93 

history  of,  93 
Caspian  Sea  region,  original  home 

of  grape,  215 

Catalogues,  study  of,  exercise,  115 
Caterpillar  of  butterfly,  225 

red-humped,  233 

Caulicle  of  bean  and  pea,  illustrated, 
40-41 

of  corn,  43 
Cauliflower,  105 

Ceanothus  as  a  soil  indicator,  120 
Celeriac,  93 

illustrated,  94 
Celery,  106 

illustrated,  107 
Cell,  description  and  function  of,  16 

parenchymal,  31 

-sap  defined,  19 

-wall,  17-19 

Cereal  crops,  injury  by  insects,  223 
Change,  universality  of,  4 
Charcoal,  for  stratification,  46 
Chard,  illustrated,  92 
Cherries,    geographical   distribution 
of,  190 

history  of,  189 

pollination  of,  190 


Chestnut,  194 

Chicory,  described  and  illustrated, 
94 

uses  of,  94 
Chile  saltpeter,  130 
China  explored  for  wild  plants,  7 
Chip-budding,  76 
Chives,  101 

illustrated,  102 
Chlorophyll  and  photosynthesis,  33 

bodies,  247 

defined,  31 

examination  of,  38 
Chloroplasts,  function  of,  20 

illustrated,  31 

Chromoplasts,  description  of,  20 
Chrysalis  form  of  butterfly,  225 
Cider,  a  by-product,  291 
Cippoletti  weir,  150 

construction  of,  exercise,  155 
Citric  acid,  a  by-product,  291 
Citricola  scale,  illustrated,  237 
Citrus  fruits,  history  of,  196 

marketing  of,  198 

study  of,  exercise,  204 
Cleft-graft,  79-80 

illustrated,  80 
Climbing  vines,  302 
Cocoon  of  butterfly,  226 
Codlin-moth,  control  of,  229 

illustrated,  228 

study  of,  exercise,  244 
Cold  in  relation  to  orchards,  118 
Coldframes,  51 

used  for  cuttings,  66 
Cold  storage,  essentials  of,  271 

exercise,  276 

temperatures,  272 

treatment  of  material  in,  272 
Coleoptera,  225 
Collards,  105 
Colorado  potato  beetle,  98 

River,  overflow  of  in  1906,  146 
Colors  of  flowers,  cause  of,  20 
Commission-men,  278 
Concord     grape,     an     outstanding 
variety,  4 


314 


HORTICULTURE  FOR  SCHOOLS 


origin  of,  215 
Cone-bearing     trees,    dissemination 

of  seeds  of,  44 
Consumer's  dollar,  288 
Control  of  codlin-moth,  229 

of  insects  by  parasites,  238 

of  plum  curculio,  236 
Cooperation,  benefits  of,  283 

examples  of,  284 

in  marketing,  281 
Conn  described  and  illustrated,  64 
Corn,  parts  of  seed,  43 
Corolla,  function  of,  159 
Cost  of  marketing  oranges,  288-289 
Cotton,  injury  by  insects,  223 
Cottonwood,  dissemination  of  seed 

of,  44 

Cotyledons,  39 
Cover-crops  in  orchards,  133 

in  relation  to  fertilizers,  133 

prevent  leachingj  130 
Cowpea,  110 

Cresol,  a  by-product,  290 
Cress,  107 
Cross-fertile,  defined,  162 

pollinated,  161 
Crotons,  propagation  of,  56 
Crown-gall,  252 

exercise,  259 

of  almond,  192 
Cucumber,  squirting,  45 
Cucumbers,  1KJ 
Cucurbitoua  crops,  113 
Cultivating  vegetables,  88 
Cultivation  of  blackberry,  211 

of  orchards,  127 

of  strawberry,  208 
Curculio  on  peaches,  186 

plum,  235 
Curl-leaf,   a  disease  of  the   peach, 

185 
Currant,  climatic  requirements,  212 

propagation  of,  56 

pruning  and  care  of,  213 

Zante,  221 

Curves  preferred  to  straight  lines, 
300 


Cuttings,    apparatus    for    growing, 
65-66 

different  types  of,  58-60 

hardwood,  exercise,  67 

herbaceous,  exercise,  67 

media  for,  65 

of  coniferous  plants,  62 

of  grape,  216 

progagation  by,  57,  67 

semi-hardwood,  63,  67 

softwood,  described  and  illustra- 
ted, 62 

temperature,  65 

time  to  make,  60 
Cutworms,  control  of,  89 
Cydonia  as  stock  for  Pyrus,  70 
Cypress,  306 
Cytoplasm,  description  of,  19 

illustrated,  17,  19 


Damping-off ,  257 

Dandelion,  106 

Darwin,  brief  summary  of  life,  7 

book,  "Origin  of  Species, "  8 
Decay  in  fruit,  262 

process  of,  263 
Deciduous  fruits,  180 
Depth  of  planting  vegetables,  88 
De  Vries,  Hugo,  10 
Dibber,  illustrated,  90 
Dicotyledonous  plants,  43 
Diptera,  224 
Diseases,  control  of,  258 

of  currant  and  gooseberry,  214 

of  vegetables,  89 

plant,  illustrated  by  citrus  canker, 

199 
Disinfectants  for  pear-blight,   250- 

251 

Dissemination  of  seeds,  44,  52 
Distillate  as  contact  spray,  227 
Division  of  foreign  plant  and  seed 

introduction,  7 

Domestication,    brief    summary    of 
process,  6,  7 

laboratory  exercises,  14 


INDEX 


315 


Dominant  characters,  9 

Dormant  budding,  77 

Drainage  in  irrigated  regions,  154 

irrigation  and,  142 

to  prevent  soil  acidity,  153 
Dried  blood  as  nitrogen  source,   130 

fruits,  study  of,  exercise,  296 
Drupe  tribe,  180 
Drying  fruits  and  vegetables,  293 

of  fruits,  effect  of,  295 
Dye  stuffs  from  legumes,  109 


Ectoplasm,  description  of,  18 

illustrated,  17 
Eggplant,  111 
Eggs  of  red-spider,  242 
Egypt,  irrigation  in,  142 
Eight-to-one  test,  198,  263 

for  oranges,  exercise,  274 
Elephant  Butte  reservoir,  147 
Elm,  306 

dissemination  of  seed  of,  44 
Emasculation  denned  and  described, 
172 

exercise,  178 

illustrated,  173-174 
Emulsion,  227 
Endive,  107 
Endogenous  stem,  26 
English  ivy  a  ground  cover,  307 
Enzymes,  27 

action  of,  293 

their  part  in  germination,  47 
Epidermis,  illustrated,  31 

relation  to  moisture  conservation, 

36 

Euphrates  Valley,  irrigation  of,  142 
Evaporators,  advantages  of,  295 
Exogenous  stem,  26 
Exo-akeleton,  224 


Fall  budding,  77 

Family,  botanical  term,  5 

Fascicled  roots,  21 

Feijoa,  a  semi-tropical  fruit,  204 


Ferments,  action  of,  26 
Fertilization,  definition  of,  159 

illustrated,  160 

pollination,  158 
Fertilizers  for  fruits,  133 

for  mature  orchards,  128 

for  young  orchards,  127 

in  relation  to  marketing,  261 
Fibrous  roots,  21 
Fig,  fruit  of,  202 

native  habitat  of,  202 

pollination  of,  203 

Smyrna,   in   California   and   Ari- 
zona, 203 
Filament,  defined,  159 

illustrated,  158 

Filberts  in  North  America,  194 
Fir,  306 
Flat-headed    borer,    described    and 

illustrated,  230 

Floriculture,  in  Europe  and  Amer- 
ica, 3 
Florida,  citrus  canker  in,  199 

frost-injury  in,  197 

pomelo,  200 

Flowering  cherries  of  Japan,  191 
Flowers,  essential  organs  of,  160 

of  fig,  202 

parts  of,  158 

structure,  study  of,  exercise,  177 
Fly,  characteristics  of,  224 

metamorphosis  of,  226 
Forests,  injury  by  insects,  223 
Formaldehyde   solution   for  potato 

scab,  253 

Formal   style   in   landscape-garden- 
ing, 307 

France,  ravages  of  phylloxera  in,  220 
Freezing  of  blackberries,  how  pre- 
vented, 211 

Frequency  of  irrigation,  148 
Frost,  effect  on  viability,  46 

in  relation  to  citrus  fruit  culture, 
197 

plants  may  become  more  resistant, 
12 

susceptibility  to,  197,  198 


316 


HORTICULTURE  FOR  SCHOOLS 


Fruit-budding,  76 
Fruit-buds,  28,  29 
Fruit-drying,  exercise,  296 

process  of,  293 
Fruits,  deciduous,  180 

distribution  of,  exercise,  195 

injury  by  insects,  223 
Fruit-spurs,  29 

on  grape,  218-219 
Fumigation,  227 

of  citrus  trees,  199 
Functions  of  leaf,  illustrated,  32 

of  plant  parts,  20 

of  roots,  22 
Fungi,  control  of,  248 

defined  and  described,  246 
Fungicides,  139,  248 
Fungus,   illustrated   and   described, 
248 

potato  scab,  in  soil,  253 
Furrow  irrigation,  148 

Q 

Garlic,  101 

Genus,  plural  genera,  5 

Germination  of  pollen,  166,  168 

of  pollen-grains,  167 

of  seeds,  46 

special  aids  to,  49 

tests,  48 

time  required,  51 
Gladiolus,  corm  of,  64 
Gooseberry,   climatic  requirements, 
212 

propagation  of,  56 

pruning  and  care  of,  213 
Grading  of  fruit,  265 
Grafting,  77 

exercise,  84 

limits  of,  69 

materials,  82 

tool,  illustrated,  79 

uses  of,  69 

wax,  preparation  of,  exercise,  83 
Granules  in  cytoplasm,  19 
Grape,  215-221 

cuttings,  exercise,  222 


geographical  distribution  of,    216 

history  of,  215 

propagation  of,  216 

root-louse,  217 
Grapes,  American,  215 

cuttings  of,  61 
Grasses,  lawn,  306 
Grasshopper  group  of  insects,  225 

metamorphosis  of,  226 
Gravel  in  picking  boxes,  effect  of, 

264 

Grevillea  robusta,  305 
Ground  cover,  307 
Guard  cells,  31 

Guava,  a  semi-tropical  fruit,  204 
Gum  disease  of  lemon,  255 
Gunnison  River,  146 


Hardwood  cuttings,  61 

exercise,  67 

Harvesting,  time  for,  262 
Hauling,  264 

Hay  crops,  injury  by  insects,  223 
Hazel-nut,  194 

-budding,  76 

Healing-in  of  nursery  stock,  126 
Heat  and  seed  germination,  47 

leakage  in  refrigerator  cars,  269 
Heating  in  citrus  districts  to  pre- 
vent frost,  198 
Hemlock,  306 

Herbaceous  cuttings,  exercise,  67 
Heredity  and  Mendel's  law,  8 
Hexagonal  system  of  orchard  plant- 
ing, 125 
Hexapoda,  223 
Hickory,  194 
Home-garden,  plan  of,  exercise,  116 

orchard,  plan  for,  exercise,  195 
Homoptera,  225 
Honeysuckle  family,  304 
Hooke,  Robert,  discoverer  of  plant 

cell,  16 
Horse-radish,  95 

illustrated,  94 

propagation  of,  59 


INDEX 


317 


Horticulture  defined,  3 
Hotbeds,  construction  of,  50 

use  of,  50 
Hybridization,  11 

Mendel's  studies  in,  8 
Hydrangea,  305 

propagation  of,  63 
Hydrocyanic  acid  gas,  227 
Hymenoptera,  225 

I 

Illuminating  gas,  by-products  of,  290 
Imperial     Valley,     reclamation     of, 

145-147 

Improvement,  process  of  plant,  7 
Inarching,  81 
Incidental  products,  290 
Information,  market,  285 
Inlaying,  80 
Insect  enemies  of  peach,  185 

groups,  224 

metamorphosis,  225 

pests  of  citrus,  199 

pests  of  currant  and   gooseberry, 
214 

skeleton,  224 

structure,  224 
Insecticides,  exercise,  244 
Insects  and  their  control,  223 

as  carriers  of  pear  blight,  250 

as  pollen  carriers,  165 

control  of  vegetable,  89 

grape,  220 

injurious  to  apple,  182 

injurious  to  plums,  188 

mouth-parts  of,  226 

study  of,  243 

Inserting  the  bud,  illustrated,  75 
Inter-cropping  in  orchards,  128 

-fertile  varieties  of  cherries,   175 

-grafting,  6 

-planting  for  pollination,  169 

-sterile,  defined,  162 

-sterile  varieties  of  cherries,  175 
Irish  potato,  95-98 
Irrigation,  acreage  under,  in  United 
States,  144 


and  drainage,  142 

history  of,  142 

importance  of,  155 

in  humid  regions,  144 

in  United  States,  exercise,  157 


Japan,    flowering    cherries    of,    191 

use  of  Wisteria  in,  303 
Jelly,  a  by-product,  291 
Jerusalem  artichoke,  95 
Jobber,  279 

functions  of,  279-280 
Jujube,    a   semi-tropical   fruit,    204 
June-budding,  77 


Kale,  105 

Kentucky  blue-grass,  306 

Kerf-graft,  80 

Kerosene  as  contact  spray,  227 


Labeling     of     pollinated      flowers, 

174 

Landscape-gardening,  defined,  297 
Landscape,  natural,  study  of,  308 
Larva,  parasitized,  239 
Larval  form  of  insect,  225 
Lateral  buds,  28 
Lawn,  a  part  of  landscape  plan,  298 

grasses,  306 
Laws    regarding    commission    men, 

279 
Layering,  54 

Chinese,  56 

compound,  55 

continuous,  66 

exercise,  67 

mound,  56 

pot,  56 

serpentine,  65 

simple,  55 

time  for,  57 

tip,  described,  55 

trench,  described,  56 
Laying  out  orchard,  exercise,  140 


318 


HORTICULTURE  FOR  SCHOOLS 


Leaf  characteristics  of  grapes,  lab- 
oratory study,  222 

cross-section  of,  31 

-cuttings,  58 

-roller,  apple  tree,  231 
Leaves,  functions  of,  31 

netted- veined,  43 

parallel- veined,  43 

parts  of,  30 

structure  of,  30 

types  of,  30 

Lecanium  scale  described,  237 
Leek,  102 
Legumes,  109 

Lemon  flavoring  extract,  a  by-prod- 
uct, 291 

Lepidoptera,  224 
Lettuce,  107-108 
Leucoplasts,  function  of,  20 
Life    history    of    codlin-moth    de- 
scribed, 228 

of  insects,  228 

of  leaf-roller,  232 

of  webworms,  234 

of  woolly  aphis,  239 
Lime-sulfur  for  shot-hole  fungus,  256 

spray  for  anthracnose,  214 
Linden,  dissemination  of  seed  of,  44 
Lippia  canescens,  306 
Live-stock  products,  injury  by  in- 
sects, 223 
Living  plant,  16 
Location  for  orchard,  120-122 
Locusts,  reference  to  in  Old  Testa- 
ment, 223 

Loganberry,  origin  of,  211 
Loquat,  a  semi-tropical  fruit,  204 
Lovett  strawberry  as  pollinizer,  177 

M 

Machinery  for  spraying,  138 
Maggot  of  fly,  226 
Mahonia  Aguifolium,  304 
Mallet-cutting,  63 
Management,  orchard,  117 
Map  of  nature's  planting,  309 
Maple,  306 


dissemination  of  seed  of,  44 
Marketing,  278 

and  selling  stage,  260 

cost  of,  287 

of  citrus  fruits,  198 

system,  defects  in,  280 
Market  preparation,  260 

prices,  study  of,  exercise,  116 

study  of,  exercise,  273 
Marmalade,  a  by-product,  291 
McLaren,  John,  308 
Measurement,  water,  149 
Measuring  worms,  233 
Mechanical  injury,  effect  on  viabil- 
ity, 47 

Media  for  germination,  48 
Membership  in  cooperative  societies, 

282 

Mendel,  Gregor,  an  Austrian  monk,  8 
Mendel's  law,  9 
Metamorphosis,  225 

examples  of,  225 

of  fly,  226 

of  grasshopper,  226 

reasons  for,  226 
Micropyle,  40-41 

Mildew  on  currant  and  gooseberry, 
214 

on  roses,  etc.,  252 
Milkweed,  dissemination  of  seed  of, 

44 

Miners'  inch,  149 

Miscible    oil    for    control    of    leaf- 
roller,  232 
Mistletoe,  dissemination  of  seed  of, 

44 
Mite,  brown,  241 

control  of,  242 

two-spotted,  241 

Moisture,  effect  of,  on  young  plants, 
52 

in  relation  to  orchards,  118 

relation  to  germination,  47 
Monocotyledonous  plants,  43 
Monoecious,  definition  of,  160 
Mormons   and   irrigation   in   Utah, 
143 


INDEX 


319 


"Mother  of  vinegar,"  291 
Mouth-parts  and  insect  control,  227 

of  butterfly,  226 

of  insects,  226 

Movement  of  sap  in  trunk,  25 
Muir,  John,  quoted,  4 
Mulching  of  strawberries,  208 
Muskmelons,  114 
Mustard,  106 
Mutation  theory,  10 

N 
Native  vegetation  an  index  to  soil 

type,  120 

Natural    lines  in  landscape-garden- 
ing, 309 

selection,  8 

style  in  landscape-gardening,  308 
Nature's  plantings,  308 
Navel  orange,  origin  of,  197 
Nectarine,  185 

on  peach  trees,  10 
New  Mexico,  irrigation  in,  143 
Newtown    Pippin    apple,     an    out- 
standing variety,  4 
Nicotine-sulfate  spray,  233,  240 
Nightshade,  deadly,  5 

exercise  with,  14 

family,  4 

Nitrification,  130-131 
Nitrogen  as  fertilizer,  129 

sources  of,  129 

Nova  Scotia,  plums  grown  in,  187 
Nozzles  for  spraying,  138 
Nucleus,  description  of,  18,  19 

illustrated,  17,  19 
Nursery  stock,  care  of,  123 

trees,  inspection  of,  123 
Nuts  in  North  America,  191-195 


Oak,  305 
Offsets,  63 
Oil,  olive,  202 

Oleander,  propagation  of,  56,  63 
Olive,  climatic  requirements  of,  201 
history  of,  201 


oil,  292 

pickles  and  oil,  202 

propagation  of,  201 
Onion,  99 

climate  adapted  to,  100 

flower,  illustrated,  100 

insects,  101 

propagation  of,  100 
Ontario,  Canada,   as  peach  center, 

184 

Optimum  temperature  for  germina- 
tion, 47 
Orange,  cost  of  marketing,  288-289 

test  for  ripeness  of,  263 

varieties  differ  in  frost-resistance, 
198 

Washington  Navel,  origin  of,  197 
Orchard,  laying  out  and  staking,  123 

management,  117 

patterns,  124 

trees,  study  of,  exercise,  195 
Origin  of  species,  8 
Ornamental  plants,  use  of,  297 
Orthoptera,  225 
Osier,  propagation  of,  56 
Osmosis,  exercise  to  illustrate,  36 

the  process  described,  22 
Ovary,  illustrated,  158 
Ovule,  illustrated,  158 
Oxygen  and  seed  germination,  47 

used  by  leaf,  32 


Packing-house  operations,  265 

of  fruit,  exercise,  273 

purposes  of,  265 
Palisade-cells  and  photosynthesis,  33 

of  leaf,  31 
Pappus,  44 
Parasitic  insects,  238 
Parenchymal  cells,  31 
Paris  green,  exercise,  244 
Parsley,  95,  108 
Parthenocissus  quinquefolia,  302 

tricuspidata,  302 
Patch-budding,  76 
Patch,  Edith  M.,  240 


320 


HORTICULTURE  FOR  SCHOOLS 


Pea,  110 

germination  of,  40 
Peach,  diseases  of,  185 

history  of,  184 

in  North  America,  184 

insect  enemies  of,  185 

roots  for,  184 

rosette,  258 

-tree  borer,  185 

yellows,  illustrated,  257 
Pear-blight,  183,  249-251 

geographical  distribution  of,  183 

history  of,  182 

-leaf  rust-mite,  243 

soils  adapted  to,  183 
Pears  grafted  on  quinces,  70 

pollination  in  relation  to,  183 

resistant  to  pear  blight,  251 
Peas,  color  of  according  to  Mendel's 
law,  9 

cultivation  of,  110 
Pecan,  193 
Peppers,  112 
Periwinkle,  307 
Persimmon,    a    semi-tropical    fruit, 

204 

Petal,  illustrated,  158 
Petiole  of  leaf,  30 
Phenomenal  berry,  212 
Philadelphus,  304 

coronarius,  305 
Phloem,  illustrated,  24 
Phosphorus  as  fertilizer,  131-132 

properties  of,  131 
Photosynthesis  and  respiration,  33 

defined  and  illustrated,  32 
Phylloxera  of  grape,  220 
Picking  of  blackberries,  211 

of  fruits,  264 
Pickles,  olive,  202 
Picric  acid,  a  by-product,  290 
Pistache,  194 
Pistil,  illustrated,  158 
Pistillate  flowers,  160 
Pith,  illustrated,  24 
Plan,  landscape-gardening,  298 
Plans  for  garden,  90 


Plant-breeding  a  science,  10,  11 

-cell,  origin  of  term,  16 

diseases,  246 

improvement,  purposes  of,  13 

-lice,  225,  238 

materials,  301,  309 

pathology,  a  science,  246 
Planting,  50 

-board,  126 

of  grapes,  217 

of  trees,  exercise,  140 

vegetables,  87 
Plasmolysis,  definition  of,  18 

exercise  to  illustrate,  37 
Plastids,    description    and    illustra- 
tions of,  20 

Plowing  for  vegetables,  87 
Plum  curculio,  illustrated,  235 

gouger,  illustrated,  236 
Plums,  history  of,  186 

geographical  distribution  of,  187 

Japanese,  186 

North  American  species,  187 

pollination  of,  189 
Plumule,   illustrated  and  described, 
40,  41 

of  corn,  43 
Poison  oak,  305 
Pollen,  collection  of,  170 

of    potato    not    viable    in    North 
America,  6 

storage  of,  171 

transportation  of,  164 

-tube,  40 

viability  of,  162,  169 
Pollen-grains,  artificial  germination 
of,  exercise,  178 

germination  of,  artificial,  168 

germination  of,  illustrated,  167 

illustrated,  162-163 

study  of,  exercise,  178 

where  produced,  159 
Pollination  and  fertilization,  158 

artificial,  described,  170 

definition  of,  159 

of  almond,  192 

of  blackberry,  211 


INDEX 


321 


of  fig,  202,  203 

of    strawberries,    caution    regard- 
ing, 208 

Pollinizers,      commercial     consider- 
ation in  choosing,  176-177 
Pome  tribe,  180 
Pomegranate,  a  semi-tropical  fruit, 

204 

Pomelo,  history  and  geography  of, 
200 

in  California  and  Florida,  200 
Potash,  132 

Potassium,  availability  of,  133 
Potato,     classification    of,    botani- 
cally,  6 

diseases,  97 

fertilization  of,  97 

Irish,  95-98 

origin  of,  95 

planting,  96 

-scab,  253 

statistics  concerning,  96 

sweet,  98 

Potentilla  tribe,  180 
Precooling,  270 

Predaceous  insects,  illustrated,  239 
Prince  Edward  Island,  plums  grown 

in,  187 

Problems  in  irrigation,  157 
Products,  value  of  in  irrigated  por- 
tions of  United  States,  144 
Project,  citrus,  exercise,  205 

deciduous  fruit,  exercise,  195 

diseases  affecting,  259 

exercise,    fertilization    and    polli- 
nization,  179 

study  of,  52 

study  of  landscape,  exercise,  310 

vegetable,  116 

Prologs  of  measuring  worm,  233 
Propagating    oven,    described    and 

illustrated,  66 
Propagation,  asexual.  53,  69 

by  seeds,  39 

of  blackberry,  55 

of  grape,  216 

of  olive,  201 


Protoplasm,  description  of,  17,  18 
Prune,  defined,  187 
Prunes,  drying  of,  294,  188 
Pruning  in  relation  to  marketing,  261 

of  blackberries,  210 

of  currants,  212 

of  fruit-trees,  134-137 

of  gooseberry,  212 

of  grapes,  217 

of  raspberry,  212 

of  young  tree,  127 

-saw,  illustrated,  136-137 

-shears,  illustrated,  137-138 

tools,  136 

-tools  as  carriers  of  pear-blight,  250 

trees,  exercise,  140 

young  trees,  134-135 
Prunus  as  stock  and  cion,  70 
Prussic  acid,  a  by-product,  291 
Pumpkins,  115 

germination  of,  42 
Pupal  stage  of  insect,  225 
Pure    cultures    in    vinegar    manu- 
facture, 291 
Pyrus,  grafts  of  on  Cydonia,  70 

Q 
Quince,  184 

Quincunx  system  of  orchard  plant- 
ing, 124 

R 
Radish,  98 

Raffia  used  in  budding,  74 
Railroad    in    relation    to    fruit    in- 
dustry, 267 
Raisins,  drying  of,  294 

history  of,  220 

method  of  curing,  221 

-seed  meal,  a  by-product,  291 
Raspberry,  212 

propagation  of,  55,  59 
Recent  irrigation,  143 
Recessive  characters,  9 
Reclamation  service,  143 
Red-humped  caterpillar,  control  of, 
233 

exercise,  244 


322 


HORTICULTURE  FOR  SCHOOLS 


Red-spider,  citrus,  241 

illustrated,  240 
Refrigeration,  exercise,  276 

history  of,  268 

limitations  of,  269 
Refrigerator  car,  269 
Relationships,  plant,  5,  6 
Reproduction,  sexual,  39 
Reservoirs,  storage,  147 
Resistance  to  frost,  12 
Respiration  and  photosynthesis,  33 

in  leaf,  32 
Rhizoctonia,  256 
Ring-budding,  76 
Riparian  rights,  151 
Ripeness    of    oranges,    how    deter- 
mined, 198 

process,  261 

Riverside,  California,  home  of  origi- 
nal navel  orange,  197 
Roosevelt  dam,  147 
Root-cap,    illustration  and   descrip- 
tion, 21,  22 

crops,  92 

-cuttings,  59 

-grafting,  78 

-hairs,  22,  23 

-louse  of  grape,  220 

-rot,  256 
Roots  as  storehouses,  23 

growing  portions  of,  34 

trimming    of    in    nursery    stock, 
126 

tuberous,  63 

types  of,  21,  34 

Rosa  rugosa,  propagation  of,  59 
Rose,  family,  members  of,  180 

propagation  of,  63 

tribe,  180 
Rosette,    a    disease    of    the    peach, 

185 

Round-headed  borer,  metamorpho- 
sis of,  231 

Rubber  plants,  propagation  of,  56 
Runners,  57 

Rust-mite,  pear-leaf,  243 
Rutabaga,  99 


S 
Saccharimeter  for    testing    grapes, 

262-263 

Saddle-grafting,  81 
Salt  River  Valley,  147 
Sanderson,  figures  on  insect  injury, 

223 
San  Jose  scale,  185,  238 

control  of,  238 
Saprophytes,  defined,  247 
Saturated  atmosphere,  118 
Savoy  cabbage,  104 
Scale  insects,  237 

San  Jose,  238 
Sea-kale,  106 
Seed  dissemination,  44 

propagation  by,  39 

resting  period  of,  45 

storage  of,  45 

structure  of,  39,  51 

testing,  48 

vegetable,  87 
Selective  absorption,  18 
Self-fertile,  161,  175 

-fertility  of  Bartlett  pear,  176 

-pollinated,  161 

-sterile,  defined,  162 

-sterility  of  Bartlett  pear,  176 
Semi-hardwood  cuttings,  63,  67 

-tropical  fruits,  196 
Sepal,  illustrated,  158 
Shallot,  102 

Shapes  of  plant-cells  illustrated,  17 
Shield-budding,  71 
Shoot  of  grape,  217 
Shot-hole  fungus,  255 

remedies  for,  256 

Shrubbery,  grouping  of,  according  to 
height,  300 

how  grouped,  298 
Shrub  planting,  299 
Side-graft,  illustrated,  82 

-grafting,  81 
Sieve-tube,  24 

Size  of  fruits  subject  to  variation,  12 
Small-fruits,  206 
Smyrna  fig,  pollination  of,  203 


INDEX 


323 


Smythe,    account    of    irrigation    in 

Utah,  143 
Snout  beetles,  235 
Snowball,  propagation  of,  56 
Soaking  seed,  exercise  in,  52 
Sodium  nitrate,  130 
Soils  adapted  to  apple,  181 

to  pear,  183 

to  pecan,  194 

to  strawberry,  206 

for  fruit-trees,  119 

for  vegetables,  86 
Solanacese,  5 
Solanum,  a  group  of  plants,  4 

carolinense,  4 

nigrum,  4 

Solids,  soluble,  in  oranges,  198 
Solution  for  drying  prunes,  188 
Sorrel  as  a  soil  indicator,  120 
Sources  of  plant-foods,  34 
South    America    explored    for    wild 

plants,  7 

Soybean,  110-111 
Species  defined,  5 
Sphagnum  moss  as  packing  for 

strawberry  plants,  207 
Spiders,  223 
Spinach,  106 
Spiraea  Vanhouttei,  303 
Spore  sacs  of  fungi,  248 
Spores  of  fungi,  247 

how  distributed,  247 
Sports  in  plant  life,  10 
Spray,  contact,  227 

-gun,  139 

machinery,  study  of,  141 

mixtures,  exercise,  259 

-rods  and  spraying,  138 
Spraying  for  codlin-moth,  229 

of  citrus  trees,  199 
Spruce,  306 
Spur-budding,  75 

of  grape,  217 

-pruning,  218 
Square  system  of  orchard  planting, 

124 
Squashes,  115 


Stamens,  functions  of,  159 
Staminate  flowers,  160 
Starch,  test  for,  38 

changed  to  other  materials,  262 

-content  of  corn,  12 
Stem-cutting,  60 
Stems,  growing  portions  of,  35 

growth  of,  27 
Stick-tights,   dissemination   of   seed 

of,  44 

Stigma,  condition  of  when  receptive, 
174 

function  of,  159 

illustrated,  158 
Stipules,  30 
Stomata,  exercise,  37 

in  the  leaf,  31 
Storage,  advantages  of,  272 

cold,  270 

common,  270 

reservoirs,  147 
Stored    goods,    injury    by    insects, 

223 
Straight  lines,  when  permissible  in 

landscape  work,  301 
Stratification,  exercise,  52 

of  seeds,  45 
Strawberry,  cultivation  of,  208 

everbearing,  209 

geographical  distribution  of,  206 

harvesting  and  packing  of,  209 

history  of,  206 

mulching  of,  208 

planting    systems    for    the,    207, 
208 

soils  adapted  to,  206 

transplanting  of,  207 
Streams,  diversion  of,  144,  147 
Structure  of  insects,  224 

of  plant-cells,  17 
Style,  illustrated,  158 
Success  in  orcharding,  140 
Sucker,  defined,  59 

of  grape,  217 
Sugar  changed  by  leucoplasts,  20 

percentage  in   grape  and  orange 
juice,  263 


324 


HORTICULTURE  FOR  SCHOOLS 


Sulfur,   atomic,  for  red-spider  con- 
trol, 242 
a  fungicide,  251 

Sulfuring  of  fruits  and  vegetables, 
294 

Sultana  grape,  221 

Sultanina  grape,  221 

Summer  pruning,  136 

Sunshine  and  fruit,  119 

Super-phosphate,  132 

Swamp  lands,  drainage  of,  154 

Sweet  potato,  98 


Tannin,  extract  of,  a  by-product,  291 
Tap-roots,  21 

Telegram,  examples  of,  in  market- 
ing oranges,  285 
Temperature,  effect  of,  52 

for  seed  storage,  45 

its  relation  to  decay,  268 

optimum  for  germination,  47 
Tent-caterpillar,  234 
Terminal  buds,  28 
Termite,  231 
Testa,  40 
Thinning  of  fruit,  140 

vegetables,  89 

Thistle,  dissemination  of  seed  of,  44 
Thomas  slag  a  source  of  phosphorus, 

132 

Thompson's  seedless  grape,  221 
Tile  drainage  for  alkali,  152 
Tillage  of  bearing  orchards,  127 
Tomato,  112-113 

-worm,  study  of,  exercise,  244 
Tongue-grafting,  78 
Tools,  vegetable,  90 
Top-budding,  77 
Topping  budded  trees,  75 
Touch-me-not,  dissemination  of  seed 

of,  44 

Tracheal  tube,  24,  25 
Transpiration,  exercise  in,  37 

in  leaf,  31 
ranspianting,  51 
T  vegetables,  88,  115 


Transportation  of  fruit,  267 

stage,  260 
Trees,  growing  portions  of,  36 

selection  of,  122 

use    of    in    landscape-gardening, 

299 

Trench  for  planting  cuttings,  66 
Truck-crops,     injury      by     insects, 

223 

Trunk  of  grape,  217 
Tuber,  64 

crops,  92 

cuttings,  58 

Tubercles  on  legumes,  109 
Tuberosum,  5 

Turgidity,  exercise  to  show,  37 
Turgor  in  the  cell,  19 

in  leaf,  31 
Turnips,  99 
Twig-budding,  75 
Tying  of  bud,  74,  75 


Uncompahgre  project,  144 
Utah,  irrigation  in,  143 


Vacuoles,  description  of,  19 

illustrated,  17 

Van  Teighen  cell,  illustrated,  166 
Variation,  forms  of,  12 

of  plants,  7,  8 
Varieties,  numbers  of,  3,  4 
Vascular  bundles,  24-26 
Vegetable-growing,  3,  86 
Vegetables,  study  of,  exercise,  115 
Veneer-budding,  76 

-grafting,  81 
Viability  of  seeds,  46 
Viburnum  Opulus,  304 

Tinus,  304 
Vinca  minor,  307 
Vinegar,  manufacture  of,  291 

quick  method,  292 
Vines,  use  of,  302 
Virginia  creeper,  302 
Vitis  vinifera,  215 


INDEX 


325 


w 

Walnut,  192-193 

blight,  193 

harvesting  of,  193 
Warfield    strawberries,   problems  in 

pollinizing,  177 
Wasps  as  pollination  agents,  in  figs, 

203 
Water,  application  of  to  land,  148 

effects  of  large  bodies  of,  121 

measurement,  149 

right  legislation,  161 

rights,  151 

sources  of,  144 

-sprout  of  grape,  217 

-table,  influence  of  irrigation  on, 

154 

Watering  vegetables,  89 
Watermelons,  114 
Weather   conditions  in  relation   to 

marketing,  261 
Webworms,  fall,  234 


Weir  measurement,  150 
Whip-grafting,  78-79 
White  pine  blister-rust,  214 
Wild    plants   of   America   domesti- 
cated, 7 

Willows  as  soil  indicators,  120 
Wilting,  cause  of,  19 
Winds,  119 
Wisteria,  303 
Woolly  aphis,  control  of,  240 

life  history  of,  239 
Wrapping  of  fruit,  266-266 


Xylem,  24-26 


Yellows,    a    disease  of  the  peach, 

186 

Z 

Zante  currants,  221 


